another mileage question on 2006

[evangelos]

hello all,

history:

i purchased a 2006 Jetta TDi with manual transmission in the summer with 90K km's that  got chipped within 2 weeks of the purchase.

i got the strongest map the stock clutch can handle - alligator map.

summer/winter driving distances are the same, shift gears for the most part is below 3000rpms, tire pressure is 40psi in the summer on 18" and 16" in the winter, 60H/40C, very little use of AC in summer, normal heat use in winter.

in the summer i will barely get 700km/tank and the winter is 600km/tank.

the engine is lively, boost is strong and kicks in at 1900rpm and pulls till redline. boost is set at 18psi.

observations:

* when we had the cold spell a few weeks past the engine started very easily on the first crank at -30C

* very good acceleration

* no black smoke on acceleration in the humid montreal summers and naturally same results during the winter

* summer tires are General UHP 225 35 18

Questions:

where can i start trouble shooting this concern?

could this be solved by dropping a few psi numbers on boost?

what mileage are you fellas getting?

evan

[Quantum TD]

It's hard to compare modified to unmodified PD MPG figures. You'd do better on the TDI forum. Those guys love to mod the TDI. Here, most people convert TDis to m-TDIs.

Having said that, my only PD experience is with a customers car. They have a 2004 PD automatic with about 90K miles on it. They claimed to get about 44 MPG out of it consistently going about 70-80 MPH on the highway. When new, they claimed about 48 MPG, and it's slowly been dropping over the past 4 years. My suspicion is that it had something to do with the new ULSD, but it also may have something to do with the timing belt. Because the injectors and the cam run off the same gear, timing easily affected by a stretched timing belt.

I'd say check your timing:

http://forums.tdiclub.com/showthread.php?t=215202&page=1

If that doesn't help try the TDI forums.

I just did thier timing belt. We'll see if helps at all. If thier MPG gets worse, I'll have to do the timing adjustment too.