Sunday, October 1, 2017

Porsche Cayman S Brakes

I do track days in my 2006 Porsche Cayman S.  The car is basically stock.  This article is a collection of my thoughts around the topic of brakes.


When I got the car it had a little over 60k miles on it.  I replaced the brake pads with Hawk HPS.  They seemed OK but not really an improvement over stock.  At Putnam Park and Autobahn I did notice these pads would start to fade when hot so I switched to Hawk Street/Race pads which made a huge difference.  These Street/Race pads are basically race pads that work down to cold temperatures.  They are noisy and create copious amounts of dust like any other race pad so its not something you actually want to drive around with daily but they do work for the street, unlike race only pads.  The nice thing about these is you can swap them in at home and drive to/from the track with them and be safe.  The noise when stopping at times is only somewhat embarrassing but not enough to be worth the hassle of swapping pads at the track.  The stopping power is more than double the stock or HPS pads.  They create far more friction for the same pedal pressure.  So much that it takes some getting used to as the first few times you hit the brakes after swapping them in you are surprised by how hard it stops with such little effort.  Once you get used to driving with them, swapping back to the street pads feels a bit alarming at first.

Tire Rack produced this chart showing the various Hawk brake pads:
Hawk Brake Pad Comparison - Tire Rack

MU is the coefficient of friction, higher means more friction.  More friction means more braking force for a given pedal pressure.  Notice that most race pads do not work well at low temperatures which makes them a problem for street use.  In this case low temperature is often well above ambient.  As you can see some of the pads perform very poorly below 300F.  In addition to the problems at low temperatures, they are generally very noisy and can produce copious amounts of dust too.


Most Porsches come from the factory with drilled rotors.  The reason drilled rotors became popular is performance applications decades ago was because of a gas layer that would form at high temperatures cause interference between the pad and rotor.  Modern performance brake pads have significantly reduced this problem, and better solutions have evolved.  One of the problems with drilled rotors is they can crack under the temperatures and stress of track use.  Mine started cracking at Road America which is particularly hard on brakes.  Here is a photo showing the small cracks starting to form.
This rotor is not too bad but those cracks can grow.  In extreme cases, the rotor can break off in chunks which is dangerous.  The best solution for track duty is slotted rotors.  I switched my rotors to Sebro slotted.  This photo shows the slotted version next to the factory rotors.

The slots in the rotors help clear the gas layer but don't tend to crack like the drilled rotors.  The slotted rotors also have more metal mass to absorb more heat.  This will help slow down the heating some under hard braking.  The heat can then be released between corners when the brakes are released.


Brakes slow the car down by converting mechanical energy (momentum) into heat.  Changing the momentum of the car requires power (HP).  The engine provides the power to accelerate and the brakes provide the power to decelerate (in conventional powertrains).  Normally the braking power capability is much higher than the engine power.  This is a large amount of energy that the brakes much dump as heat.  The rotors require airflow to facilitate this cooling.  The Cayman/Boxster and 911 sports cars have brake cooling ducts to guide more air to the rotors.  The Porsche GT (GT2, GT3, and GT4) cars have more effective cooling ducts that can be fitted to the other 911 and Cayman/Boxster models.  I installed GT3 cooling ducts on my Cayman S.

Here is a photo of the factory cooling duct.
Here is a comparison of factory versus GT3 cooling ducts.
 Here is the GT3 cooling duct installed.

Brake Hoses

The brake hydraulic system has very high pressures.  Most of the system uses steel allow lines to route the fluid between the brake components.  However, the brake calipers must move relative to the chassis so hoses are required for this part.  Those hoses are generally main of reinforced rubber.  The problem is that even though these hoses are reinforced to reduce expansion, they still do exhibit some expansion under high pressures.  The fix for this is stainless steel hoses.  There are several available in the aftermarket but make sure you use DOT and TUV approved hoses.  

Brake Fluid

Brake fluid is NOT created equal!  Also, good quality fluid with high wet and dry boiling points is very important, especially in a car that will be used on the track.  When driving at speed on the road course, the car will see repeated heavy braking for 25 minutes or more at a time.  This will cause the calipers to heat up.  If the temperature gets high enough, the fluid can boil.  When this happens the boiling displaces fluid in the caliper with gas.  The displaced fluid is pushed back into the master cylinder.  The gas is compressible.  The next time you hit the brakes the pedal goes to the floor with little to no braking at all.  This is a very dangerous situation and must be avoided.  Any decent track inspection checklist will include replacing the brake fluid just before the event, generally within 30 days.  This is a simple procedure and even expensive brake fluid is far cheaper than loosing brakes at the track.  A good DOT 4 brake fluid is Motul 600 or 660 which is available from many parts stores that sell performance products.  There are other high performance brake fluids.  Pay attention to the wet and dry boiling points.  The reason it needs to be changed so often is water will mix with brake fluid, unlike oils.  Humidity and condensation will get into the brake fluid over time.  Vehicles that do not see high brake temperatures are far less likely to have a problem.     

Tuesday, July 4, 2017

What good is a Smartwatch?

I waited a long time to even try out a smartwatch.  I don't like wearing watches in the first place, and the phone in my pocket has all the info I need.  I didn't see the use for a smartwatch.  I do however, like tracking my fitness especially with bicycling.  I had a Polar Bluetooth heart rate sensor that I used but it quit working.  I also did not like wearing it.  I wanted a better heart rate sensor so I decided to look into smartwatches.

I chose the Motorola Moto 360 Sport.  These have been around for a while and you can often find them on sale for a great price.  I think I paid $169 for mine but I have seen them under $100 sometimes.  It has the optical heart rate sensor.  It came with Android Wear 1.5 but it should be upgraded to Wear 2.0 any day.


While I was certainly a naysayer on smartwatches, I have found more uses for mine than I thought.  I wear it every day now.  I don't think I would spend over $200 to get one but for the price I paid, I feel I am getting the value from it.

Fitness Tracking

May first use for the watch was for heart-rate monitoring during bike rides and walks.  I wanted a device that would integrate with the apps I use for tracking these activities.  I use Google Fit for my daily activity tracking.  I was using Cardio Trainer for bicycling.  I had also used My Tracks for this in the past.  It turns out that Cardio Trainer and My Tracks do not support the heart rate from this device.  Lame!  So, I switch to a more popular biking app called Strava.  This is a better app than Cardio Trainer anyway and it gives nice graphs for heart rate, as well as the rest of the data.  It also integrates with Google Fit.  Very nice.


Sometimes it would be handy to see notifications without pulling the phone from my pocket.  I know this is a first world problem but what the heck.  Some of the more useful things are:
  • Rejecting callers.  Spam calling is totally out of control and it is very handy when one of these calls comes in to just glance at the caller info on the watch, and swipe it away.  
  • Navigation.  I didn't expect this one.  I am all about stopping distracted drivers.  People need to hang up and drive.  You should not take your eyes off the road.  I was using Google Maps to navigate on a trip.  The phone was on the seat, not visible while driving.  I was on a long straight stretch of interstate and wondered how far it was to my next turn.  I glanced at my watch and there it was.  Just a small message with the distance to, and direction of the next turn.  Nice.  
  • Seeing the time and date.  It is a watch after all.  There are many useful watch faces that are informative.  It shows the time and basic info even when the screen is off.
  • Seeing general notifications.


As an amateur Android developer I wanted a device that I could write apps for if I wanted to.  Learning Android Wear development should be easier since I am familiar with Android. The first app I started for Android Wear is a remote control for my Gamin Virb Ultra 30 action camera.  I just wanted to be able to start/stop recording and maybe snap a photo using the watch as the remote.  I did get the remote working on the phone first so I could learn how to interact with the Garmin.  Once I did that, I created a wear app for the watch.  Getting the basics going was not hard.  I don't have this app done yet though.  There is a feature I depended on that Wear 1.5 does not support.  The alternative was to use the watch app in conjunction with its phone counterpart to control the camera.  That is a work in progress.

Smartphone Shopping Summer 2017 Edition


I have not posted about smartphone shopping for a while so I thought I would capture my thoughts here as some friends have been in the market.  As you know, I prefer Android devices for many reasons:
  • Open source software
  • Large Play Store full of great apps
  • Compared to other operating systems, Android allows more flexibility.
  • Google is not evil.  There are many free features and services that are best in class
  • App to app integration.  Sharing for instance.  You can share from any app to any app you want.  Nobody is forcing you down what they want.
  • Many excellent devices to choose from.  This competition is great for both price and features.
  • Micro-USB or USB-C standards.  You can buy cables, chargers, etc from whoever you want as competitive prices.
  • SD card support.  You are not stuck with the space the device is made with.  Some support Micro-SD cards up to 2TB.  
  • Access to see files, folders, data, photos, etc.  You can also simply connect to a PC and browse it like a USB memory stick.  

Brands, Skins, Preinstalled Apps

I lean heavily towards Motorola devices.  I think they offer the best value.  Other devices have higher end specs but they come with a bunch of unwanted skins and bloatware.  For instance, Samsung, LG, and HTC all have very heavy skinned versions of Android.  It is so heavy I have a hard time finding things.  Samsung also makes their own versions of basic apps that replace the Google versions.  This is just a mess in my opinion.  These are also installed in the system meaning you can't really remove them without rooting.  All of this just hogs up more device resources so that faster process and more RAM are needed because of all this bloatware.  I don't understand why these device makers continue to do this when article after article complain about it, it costs them to make and maintain it, and many users don't even want it.  Motorola has the closest to stock Android as you can get short of a Nexus or Pixel.  

It is very interesting that devices are marketed to the public showing pre-installed apps as a feature worth paying for.  To me that is like marketing a sedan with pre-installed junk welded into the trunk that you don't want and can't remove.  Now you have a less usable car.  You can't choose what is in the trunk.  Definitely get the device with the least pre-installed stuff as you can get.  Installing apps is very simple and there are many great free apps on the Play Store.  

While I have had Motorola devices almost exclusively, I have had a Lenovo tablet.  I like the hardware but the OS is terrible.  Lenovo has a bunch of bloatware in this device.  The Lenovo launcher was the worst I have ever used.  It had apps permanently in the home screen.   They wanted to force you to use their awful apps, and those they were paid to pre-install.  I was able to fix the home screen with Google Now launcher and disable all the bloatware.  I was able to even uninstall some of it.  

My Choices

So, which device would I buy if I were shopping right now?  Here are some features that I prioritize:
  • Qualcomm Quick Charge.  This is a game changer.  Many devices has other fast charging technologies but they don't really compete.  Quick Charge uses a proprietary technique to boost the voltage so that standard cables work.  You can only boost the current so far before the loss in the cable becomes a real problem.  Most chargers only support 5V charging.  Quick Charge goes up to 12V.  You can put almost 3 times the power through the same cable.  I have Quick Charge 2.0 on my 2015 Moto-X and this is a must have feature for me.
  • A big battery.  A smartphone with a dead battery is useless.  This obsession with thin is ridiculous.  Honestly, today's phones are often too thin.  I would like to have a 6,000mAh or bigger battery if I could and I would gladly put up with the extra 6mm.  
  • At least 4GB of ram.  This is important so the device does not lag when running large apps or switching between them.  Today we also have many background processes and the device needs this ram to manage it efficiently.
  • A fast 64bit multi-core CPU running at over 2GHz.  I would say a quad minimum but 6 or 8 even better.  .  
  • It must be unlocked and free of carrier software.  
  • A good camera.  These are getting better all the time so there are many good choices here.  I don't need to record at 4k but HD is needed.  I want tomething that is fast.  I want to be able to capture moments as they happen so it must open, focus, and snap very fast.
  • A decent sized screen.  I like something in the 5.5" range as my vision is not so great anymore.  I don't need over HD though.  Even 720HD would be fine for me.  The higher resolution you get, the more processing power it eats up, which also eats more battery.  
  • Must work on Verizon.  I have a love/hate relationship with Verizon.  They have clearly become evil but they simply have the best network.  I still have the old unlimited plan.  Around town I often get over 50Mb speeds.  It is rare that I don't have service even on trips.  
  • Regardless of an SD slot, the device needs at least 32GB of memory.  This is so you can install all apps and app data on the device.
  • An SD card slot.  While you want all your apps on the device, the SD card opens up tons of space for media.  This is especially important if you shoot much video.  Strore your media, photos, and video on the SD card and save the on-board memory for apps.  Ideally the device would support the full SDXC standard which means you can use cards up to 2TB (even though that size is not yet available).  Several phones do support this.  
  • NFC.  I have starting using mobile pay.  I tried Android Pay but my cards stopped supporting it.  Now I use Capital One Wallet and it generally works well.  Honestly it is still faster and easier to just use the card in most cases but I am really hoping someday we won't need a physical wallet and this is the start of that.  I just want this option.  
  • Fingerprint sensor.  While this is low on my list, and is not a must have, it is handy at times.  
  • A good old fashioned headphone jack.  This is low on my priority list but it is something to consider these days.  I tend to prefer Bluetooth anyway so I don't need this very often.  
Here are the ones at the top of my list.

Moto G5 Plus 4GB/64GB

I would get the one with 4GB Ram which is only available with 64GB memory.  This device retails for $299 which makes it a bargain.  It has 4GB ram which gives apps plenty of space without having to swap in and out.  That makes the device more responsive, especially when switching between apps.  The 64GB memory is also nice as you want all your apps and their data on the device memory versus and SD card for speed.  SD cards are great for media and data, and this device has the slot.  It is unlocked so there is no carrier bloatware and this should also make updates faster.  It has Quick Charge 3.0 for fast battery charging.  It does lack NFC for mobile pay and certain other features, if you use that.  It has a Snapdragon 625 chip set clocked at 2.0GHz so it should keep up with most apps, except maybe some of the games that need top end performance.  For the vast majority of users, this device should be a great fit.

Moto G5S Plus

Coming soon.  This is an upgrade to the Moto G5 Plus.

Moto Z2 Play

The Moto Z line is Motorola's flagship devices.  The real unique thing about them is the Moto Mods. Moto Mods are magnetically attached devices that cover the back of the phone.  Some of the most appealing for me are the batteries.   While the Moto Z devices are silly thin in my opinion, once you attach a Moto Mods battery, it is about right.  This is even better than the removable batteries of yesteryear since you can swap the Moto Mod when the device is ON.  Just pop one off and attach the other.  Some of the Moto Mod batteries also have quick charge.  Other have wireless charge.  Several options and more coming.  The Moto Z2 Play is out now, although only the Verizon locked version right now.  The website says the unlocked version is coming soon though.  This device is priced starting at $408 retail (not sure about the unlocked price) which is well below the premium phones with often cost over $700.  It has a Snapdragon 626 clocked at 2.2 GHz.  It has Quick Charge 3.0.  There is a version with 4GB of ram which is the one I would recommend but they don't have it available yet and I have not seen the price for that version.  The other Moto Z phones also look great but for most users, probably not worth the price point.  I would avoid the carrier locked versions myself.  The Moto Z Force Droid looks great except it is locked on Verizon and full of their bloatware.  It does have the shatterproof screen, a larger battery, and higher end specs which is great.

We bought one of these.  We got the Verizon only device with 32GB so it only has 3GB ram too.  We also got a battery mod with wireless charging.  Battery life even without the battery mod is excellent.  Adding the battery mod makes this a 2-day device with moderate to heavy use.  With the battery mod fitted, the device is a bit heavy.  I don't mind the weight but some may.

It has USB-C and Quick Charge 3.0 but it will not quick charge on Quick Charge 2.0 devices for some reason.  It quick charges fine on all my Quick Charge 3.0 devices including car chargers and battery backs.  On Quick Charge 2.0 devices it just charges regular.  There are good Quick Charge 3.0 accessories out there relatively cheap.  

Moto X4

This device is not actually announced yet but the leaks are getting better all the time.  We expect this to be released this fall.  If the leaks are correct, this looks like a great upper-mid tier device.  

Google Pixel 2  

This is sure to have the cleanest Android experience you can get.  You will pay for it though.  This will be the second iteration of the new Pixel phone line and hopefully they fix some of the issues they had with the first.  

Saturday, March 18, 2017

Porsche Cayman Camera Mount

I bought a Garmin VIRB Ultra 30 action camera for recording in-car video in my 2006 Cayman S (987.1).  This camera uses the same mounts as GoPro cameras and many other action cameras. I found a good windshield suction mount that works great but sometimes its nice to get an in-car perspective.  I searched everywhere for a good mounting system.  I bought a clamp that I could use on the bar behind the seats, on the engine compartment.  However, the clamp was not rigid enough. It was also lower than I would like.
Camera clamp 

I kept searching for better options. I found one for over $400 and it still did not look great.  At this point I decided In would build one.  I went to the hardware store and bought about $35 worth of 3/4" aluminum square tubing, some 8mm all-thread, wingnuts, and washers.  I cut the tube into a 22" and 2, 5" lengths.  I removed the factory bar and installed the all-thread  into the bolt holes the original bar bolts were in.  Here is what I ended up with.

No special tools were needed.  Just a drill and saw.  It seems very rigid.  Road test coming soon.

I plan to just use this for track days and other events.  Its very simple and quick to swap the original bar back in as this camera bar is built for utility, not looks.

Here is a photo taken from the VIRB in the mount.

Saturday, December 31, 2016

Owning a Mercedes E350 4matic

We bought a used Mercedes Benz E350 4matic in September of 2015.  It is a 2010 (W212) model and it had 34k miles on it.  Our daughter is off to college which is over 500 miles to drive each way.  We have made this trip many times.  The car already has over 77k miles as of this post (December 2016).

The good

This car handles very well for a luxury sedan.  Of course I said the same about the Jaguar XJ8L we had before it.  Seems that luxury cars are no longer the bouncy boats they once were. This is a great car for long road trips.  As I mentioned above, we often take this on long trips and the driver fatigue is the lowest I have had in any car.  It's very stable and it inspires confidence while also being very comfortable. Once while driving through central Missouri a car quickly veered into me as I was passing.  I had to take immediate action to avoid a collision.  I had to steer quickly to the left, using all remaining pavement, possibly even dropping the edge of the left wheels off the pavement.  We were doing over 70mph.  I was easily able to control the vehicle with confidence and we avoided any damage.  

This car is very easy to enter/exit and to drive.  My wife has RA and she says it is a great car for her since everything about it is easy.  Doors open easy, it shifts easy, etc.  

I like the paddle shifts for the automatic trans.  In this car you need them too.  More on that below.

We like the look of the car, even in silver.  I generally prefer red or blue.  Silver and black are my least favorite car colors, and sadly the most popular on Mercedes.  I don't mind it so much on this car though.  

The entertainment system is very good.  I am shocked however that is does not support Bluetooth A2DP (music streaming).  That seems ridiculous for a 2010 model.  Especially when it supports everything else.  I do mean everything too.  It supports 6 DVD/CD, PCMCIA expansion, Satellite radio, AM/FM, weather radio, and it has a connector in the glove box where you can connect USB, video, and audio.  It has a built in hard drive that you can use to store music on as well.  The sound quality is great too.  

So far it has been easy to work on.  I have only done oil changes, spark plugs, and rear brakes but those were all very simple.  The engine compartment opens up to expose the whole engine which is rare these days.  So many cars have the engine tucked under the bodywork making it hard to access the rear of the engine.  Not this car.  Here is a photo with the air cleaner removed.
Engine bay with air cleaner removed
Removing the air cleaner is a few clips and hoses, no tools needed.  You can see all the ignition coils in plain sight here.  Another great feature is that I can reset the maintenance reminders myself with no tools.  It is done with the display and steering wheel buttons.  It is a bit tricky and takes me several attempts each time but at least I can do it which is more than I can say for Volvo and Porsche.

The 270HP engine makes decent power.  This is the lowest power gas engine for this model year.  Still, it's not too bad.  The powerband is broad too for a naturally aspirated engine.  Fuel economy is OK for an AWD luxury car.  I get mid-20's on a road trip and about 20 in town.  

Tire life has been very good.  

The not so good

While the seats are very comfortable, I don't like the fake leather they use to make them.  It is much hotter in the summer than real leather.  It also has a bad feel on the skin when wearing shorts.  Much better when you have some jeans to separate you from this material.  It seems very durable and it looks good but it feels bad on your skin.  I find myself missing that fantastic Jaguar leather.

Like most newer cars, the automatic transmission favors the highest possible gear and the convertor locked.  I think the convertor locks as soon as you are moving.  This is all done for fuel economy.  The downside comes when you are merging onto the freeway.  You his a steady speed in the cloverleaf when it is constant radius.  At this point it shifts into the highest gear.  As the ramp straightens out to merge onto the freeway, the car resists downshifting.  You keep going deeper into the throttle with little response until finally it drops about 3 gears and you accelerate away.  Like I said, this is typical of modern cars.  Here is where the paddle shifts come in.  I limit the upshifts to keep the engine above 2,000rpm or so.  I can now accelerate on smoothly.  You can optimize the gear using the paddles until you get to cruising speed.  Then you just hold the upshift paddle until D is selected.   One other issue with this trans happens when going up a steep hill at low speeds.  Again the trans will hold the highest gear with the convertor locked to the bitter end.  When it does finally downshift, it can occasionally be harsh.  

Like most cars this size it is cramped for 5.  You can ride 4 with decent comfort but that 5th person in the middle is a tight squeeze.  This is not just an E-class issue of course.  You need a pretty wide car to fit 3 adults across in comfort.  It's fine across town but after an hour on the road, the back seat occupants will complain.


This car has turned my wife into a Mercedes fan.  It is very likely her next car will be a Mercedes.  She wants to consider an S-class next time for the extra room though.  I like the car too.  I would probably get the E-class again as a like the less big size.  Now they have the E400 which is basically this car with twin turbos.  

Saturday, January 9, 2016

Mercedes E350 DTC's

I have a 2010 Mercedes E350 4-matic.  At about 38,000 miles the "check engine" light came on intermittently.  I scanned it with a generic OBD scan tool and the Torque app.  It returned P0496 and P1077.  It started out setting these DTC's only once in a while, about 1,000 miles apart or more but it eventually happened more often.  I subscribed to the factory documentation and searched for the Mercedes DTC definitions but the documentation did  not show these 2 DTC's at all.  The generic definition is canister purge flow high.  I inspected the related hoses and found nothing wrong.  I searched forums and found some comments that people had fixed this with a new purge solenoid.  I removed and inspected my purge solenoid and found nothing wrong.  I checked to make sure it moved freely and sealed properly.  I noticed an adjustment on the top of the solenoid that was covered with silicone sealer.  I was able to poke the correct size allen wrench into the adjustment and adjust it.  The adjustment changed how far the valve opened when energized.  I ran the screw in a turn or 2.  I made sure the purge valve would still open but at a lower flow rate.  After driving the car for a while to let the monitors run the check engine light returned but this time 2 different codes were set: P0455 and P1085.  Neither of these were covered in the Mercedes documentation either so I checked the generic definition.  Now it said gross evaporative leak.  Interesting.  The DTC's changed so I know I was on the right track.  I turned the adjustment about 1/4 turn out (CCW) and drove the car again.  The MIL went out (so far).

Missing DTC's in the service information is a big industry problem.  I had this same issue on my Jaguar XJ8L.  What often happens is the controls are flashed with newer software which changes the DTC's but the documentation does not get updated.

It is also lame that Mercedes has 2 DTC's trip at the same time for a single detected issue.

I finally fixed the issue with a new gas cap.

Sunday, July 26, 2015

Why I love Jaguar cars

Historically I was always a Ford fan.  I had all Fords until I acquired a BMW many years ago. My wife had always loved Jaguar cars.  They were beautiful, however, in the 1980's they were one of them most unreliable cars on the road.  British Layland pretty much destroyed the brand during this period and even today many people love the looks of the car but still remember the Jaguars of those years.

In 1989 Ford purchased Jaguar and began resurrecting it.  This took a long time as Jaguar was in bad shape at the time.  I bought my first Jaguar in 2000.  It was a 1994 XJ12.  We had a Ford Crown Victoria at the time and it had over 250k miles on it.  It was time to upgrade.  We looked at replacing it with another Crown Vic but when we saw the XJ12 for sale nearby we thought, what the heck.  We always wanted a Jag so now is the time.  I got the car cheap.  It was under $14k for a car that was originally over $70k.
This was not only my first Jaguar, but also my first (and only) V12 car.  This V12 had been upgraded under Ford ownership to fix all the oil leaks and other issues that had tarnished Jaguar.  We took this car on many trips and really liked it.  We eventually sold the car with 145k miles on it.

For a while I owned both the XJ12 and a 1998 XJR.  The XJR was a fantastic car for its day.  Very quick and fast.  Compared to the XJ12, and most other cars actually, it drove like a sports car.  I seriously considered taking this car to the track.
I still love the look of that XJR.  We sold this car with over 150k on it.

While the XJR was great in my book, my wife preferred a larger car with a smoother ride.  The XJR had firm suspension and wide tires for great handling.  She never used these features though.  So we bought a 2007 XJ8L.

In 2004 Jaguar created the X350 body style of the XJ which was all aluminum.  This reduced the cars weight considerably.  The whole car was redesigned and improved.  It was also larger.  The XJ8L is the long wheelbase version so it is even larger.  The back seat has enormous legroom.  It also has air ride suspension with active shocks.  Our 2007 was the last of the X350 (2008 was a slightly altered X351).

I also bought an X-Type.
The X-Type is really based on a Ford Mondeo. Being a Ford guy I am certainly good with that.  I will say though it is not like the XJ except in looks.  It rides like a Mondeo.  The X-Type and S-Type had heavy Ford influence and parts.  The XJ, XK, and the newer cars have very little in common with Ford.  Jaguar has always made their own V8 engines.  The new Jaguars now don't have any Ford parts.

So, why to we love these cars.  It is actually hard to explain to people.  Each time we were ready to replace our Jaguar, we drove many other cars and always came back to Jaguar.  They have a particular feel that is hard to describe.  The controls  are simple and intuitive.  The ride is really fantastic.  Not the boaty ride of years ago.  Firm yet compliant.  The car does not lean in corners yet it can soften up our nasty Illinois roads.  Acceleration is very good and smooth.  The XJR and XJ8L have a very pleasing exhaust note yet no drone.  People are amazed to hear the fuel economy this 2007 XJ8L gets.  I have done as good as 32 on the highway.  I always get 27 - 32 on the highway, and about 20-22 in town.  For a car this huge I feel very good about that.  The car just glides down the highway, even on terrible roads.  It is very controlled even at high speeds and the driver feels confident going fast.  The occupants are in a serene environment even when it is not so serene outside.

Jaguar has actually won or scored very well in several JD power's awards more recently. Both the quality awards and the APEAL awards.

I do all my own work on all my cars.  Jaguars are not that hard to work on.