Tow-rig. Ooops, Touareg, the diesel hauler

In reply to Parker with too many Projects :

I usually fill up when the low fuel light pops on, or just before it.  The tank is 26.7 gallons and I usually have about 5 gallons left when I fill up and have done 515 (ish) miles.  So that's around 625 miles to dead empty.  I think the people claiming 700+ on a tank are emissions deleted, which makes a big difference in mpg, and/or do a lot more freeway driving than me.  With the tune I was getting around 24 mpg mixed, this tank untuned I suspect it'll be close to 25 mpg.  My wife, who has a longer freeway commute than me, plus drives under the speed limit on the freeway (like 50mph vs me doing 80 mph), averages 27mpg in her untuned Cayenne diesel.

I'd recommend the Malone tune vs the Darkside one.  Malone has great support and also has TCU tunes, including the free pre diesel gate tune.  I've been happy with them so far.

I'm getting 23 in terrible stop and go traffic with the Malone Stage 2.5 and Nur-Spec TCU tune. The power is impressive but it is a little twitchy at slight throttle inputs which makes it tricky to drive smoothly. I may go back to the Stage 2 tune. 

Just an FYI. The CP4 fuel pumps are fuel lubricated and cooled. They are subject to catastrophic and expensive failures caused by trash, fuel starvation, overheating, and such. The failure sends shrapnel throughout the fuel system requiring the replacement of the pump, injectors, tank, and pretty much the rest of the system. 

I have read some suggestions to not run CP4 vehicles below 1/4 tank of fuel to make sure there is enough volume to keep the pump cool.

Religious fuel filter changes will also help the lift pump keep the HPFP supplied. 

I have also read that pump failure rates are 1% in Europe compared to 7% in the US due to the lower sulfur and lubricity requirements for US fuels. The US has a Wear Scar Diameter spec of 520-microns compared to the 460-micron spec in Europe.

I have only been buying major brand fuels and I have been running Stanadyne Lubricity Formula every couple of tanks to add some lubrication back to the fuel. It may not help but I really don't want to be in the 7%. 

In reply to Toyman! :

I mean, sure, more fuel is better.  However my wife certainly doesn't do that and we've put 100k miles on her cayenne without a problem.  That doesn't mean we won't have one and it'll mechanically total the car, but I wouldn't say the 1/4 tank thing is a must do.  I do regularly change the fuel filters, so we've got that going for us.

Filled up today, 24.3mpg on this tank, basically the same as usual.  So I'm going to reflash the Stage 2 tune tonight and call it good.

Dang, mine has never gotten higher than 22mpg on the tune/DPF delete, mixed with 60% highway, and I'm babying it because I don't want to blow soot. Stock I could regularly get over 25. Injector set points and balance look good, so I'll look to Malone as a possible solution.

Flashed the tune back on after work yesterday.  Definitely a large difference in HP/torque, makes the car much more pleasant to drive and matches the Malone pre diesel gate transmission tune better too.

Cabin air filter installed.  Thought I'd ordered tpms for my winter wheels but turns out my FCP Euro order got all screwed up.  Top tip!  Don't have multiple windows to FCP open, the cart doesn't update from window to window.  So I had to return some parts that somehow I ordered instead of the ones I needed, then reorder the stuff I needed.  Need to do an oil change on this, then have the tpms installed in my winter wheels and swap those on and clean out the cowl drains at the same time.  Then it's ready to go.