I posted something similar at the mb forums and was berated for trying to compare a gl350 to a cayenne turbo. I previously had an 06 tts and was intoxicated with the offline thrust although i disliked the limited range based on a small fuel tank, imo.

I ended up picking up a gl350 diesel after having had a good experience with an ml350 bluetec with a nice combo of low end torque making around town driving pleasant and downright peppy, but my gl350 seems a bit heavy to lug around.

My main questions are how is the build quality of the 2011-14 cayennes, i recently traded my 2010 panamera turbo for literally an annoying bit of rattles and drivetrain hummm that was never solved by the dealer. The gl btw is solid and build quality feels better than the panamera.

Secondly, i am enjoying getting over 22 mpg on mixed driving with the gl, the best i could do with the 06 cayenne is 15 overall, how are people doing and does the larger fuel tank address the limited range issue.

I am willing to sacrifice some mpg s for the raw power of the tt or tts.

I am looking at some 2014 s with 155-165 sticker that have already depreciated in excess of 35K with under 5000 miles.

your thoughts.

 

That is unfortunately an issue with every manufacturer. Some people get lucky and never have an issue while others get a semi-rolling POS.

Overall the build quality is good for Porsche in general and it sounds like you just got unlucky with your PTT. The new Cayennes (2011+) seem to have a very good track record for major failures (e.g. no cylinder scoring, failed coolant pipes, etc..) compared to the early Cayennes (955s).

I believe that the "extended range" tank became standard late in the 2012 model year. So if you are looking at a 2011 or 2012 you'll want to double check if it has the 26 gallon tank or not.

As far as the MPG, the highway estimate is 22 for the CTT and 20 for the CTTS. What you'll really get will greatly depend on how you drive it. I know people that pull 30mpg out of their 996s, we get about 18 out of ours... I get right about the 23 combined estimate on my CD though in stock form and do much better when it's tuner box is installed.

 

I typically drive pretty easy with the occasional romp, i assume that with a light foot, i should be able to pull an average of 18.....what kind of range with the extend tank do owners see? 400 miles maybe, if i remember correctly on my 06 i was filling up with not much more than 300 miles..

Gnat, which manufacturer does the best tunes for the cayenne diesels

 

Some quick numbers to bone dry would be:
15mpg (city estimate) = 390 miles
18mpg (your hope/guess) = 468
22 (highway estimate) = 572

Actual CTT(S) owners will need to chime in with their real world experience.

Those of us that have done it have been using Bluespark Automotive's offering. Most have gotten the BSP with the additional boost controller, but there have been a few that just got the basic BSP unit. The Gen1 had some issues due to ECU differences between the EU and NA configurations, but they worked with Greg and seemed to have addressed it for the Gen2 box. I haven't yet upgraded to the Gen2 box myself, but the longer I go with the box off the more I'm justifying the (cheap) upgrade cost.

 

2013 Cayenne Turbo. Realistic 15 MPG combination highway, local roads and some stomping on it. Not great but worth the fun excitement and unbelievable quality of this beast.

 

I've had my 2014 CTTS for about 3 months now. What I have been seeing is roughly 300 miles per tank and roughly 24 gallons per tank fill up. I've been averaging slightly under 14 MPG with a city/hwy split of 40/60.

 

My 2013 Cayenne TT was a rattle trap. Passenger rear door, pano roof, passenger door, rear seats all rattled. Plus rear tailgate would not close all the time by the button. I got rid of the POS. Got a 2013 X5M.

 

I know this was not the question you asked - but I totally dig my '14 Cayenne Diesel and consistently get over 30 mpg.

 

I drive 110 miles daily on my cars.

The CTT gets about 16.5 overall with 90% being on freeway going 80-85MPH.

I had the previous 957 Cayenne and you are right, the range absolutely sucked. I have the extended range tank in mine and I think after 2013, it was standard on the Turbo's right? I could be wrong....

 

this is what worries me, same reason i got rid of my panamera, annoyed the hell out of me, the gl feels extremely tight and quiet, i would hate to move into a rattler...

 

since we use the gl as a 5 passenger suv, the cayenne diesel might have been a better option. does it feel peppy around town?

 

Peppy yes. All out fast, not so much.

It's no drag racer, but that torque right off idle will put you back in your seat and get it moving.

It's nearly effortless though and it's easy to get lulled into "I haven't broken 2k RPM so I can't be going THAT fast" and then look down and see you're doing 80.