Mileage issues

[fdnyguy]

Talked to Tyler and he suggested I post it. My Mk2 was rebuilt by a member here (not saying names, but the initials are ilikevwdiesel). Added a Giles IP, TT d/p, 2.25" (basically everything that was recommended). Car runs GREAT (thanks, Scott!!), but even with 21k and not driving like a moron (for the most part), I am having a very hard time breaking 40 mpg. Ive gotten a high of 55 mpg and averaged mid to high 40's with older engine. Tyler told me even Giles had to put even more miles on his before he saw an improvement With a crazy work schedule (80-100 hrs/week), I still have NOT opened up the air intake. Still using the little snorkel. Have a pvc 2.5" coupling similar to a fire hose (was coincidental!) bought @ Lowes to cut into the filter housing and seal it. I am sure that will improve performance and mileage.

But would that be the issue alone? Or have others had similar situations as well? Love to hear it. Thanks in advance.

Stay safe, stay well. Jimmy.

[bajacalal]

I know I'm asking the obvious, but what about your choice of tires and keeping them properly inflated?

[fdnyguy]

I know I'm asking the obvious, but what about your choice of tires and keeping them properly inflated?

Listen, if anyone asks dumb questions here, its me    . But to help solve the riddle, tires are 194/65/R14 on Mk3 5 star rims. And pressure checked weekly. Note that I had these tires on the car shortly before the compression rings went and rebuild by Scott. And stock pinhole exhaust system.

Thanks.

Stay safe, stay well. Jimmy.

[745 turbogreasel]

Timing and transfer pressure(dynamic advance)?

[bajacalal]

Another thing I've notices is the use of non-German air filters in the airbox causes a noticeable drop in performance and mileage. The German (Mann, Mahle) ones which are intended for TD use (as opposed to a gas engine using the same housing) are much thicker, have more pleats, and are of a different, more cotton-like material.

[fdnyguy]

Timing and transfer pressure(dynamic advance)?

Giles IP. Don't know the numbers.

Thanks.

Stay safe, stay well. Jimmy.

[fdnyguy]

Another thing I've notices is the use of non-German air filters in the airbox causes a noticeable drop in performance and mileage. The German (Mann, Mahle) ones which are intended for TD use (as opposed to a gas engine using the same housing) are much thicker, have more pleats, and are of a different, more cotton-like material.

As I posted,I havent had time to really open up the air intake. I am still using the tiny stock snorkel. From the vast info of diesel knowledge on this site, the more air the better. Looking at it, the piece I have to insert is like 5 times bigger than the tiny OEM snorkel. But I have hooked up a 3" flex hose to the fender intake and clamped it at the snorkel. I guess I should hold off asking until I complete this task. From what I have read with the Giles IP, more power = more fuel. I can live with that.  But I just got 41.4 mpg on last tank, which is 1 mpg better than what I got. With NYC driving (fast, slow, stop, repeat), I averaged 38 mpg. So competing this air intake and sealing will make an obvious difference, but when you read ppl getting 50 mpg and i cant come close to that, where else to come but the experts here?

I'll give it a shot when I find time. LOL. Anad as usual, Thanks again!

Stay safe, stay well. Jimmy.

[TylerDurden]

I imagine 38-40 is normal for NYC traffic.

I drive like an old lady on the highway to get 50mpg. Bone stock, nothing fine tuned.

[fdnyguy]

I imagine 38-40 is normal for NYC traffic.

I drive like an old lady on the highway to get 50mpg. Bone stock, nothing fine tuned.

Sometimes in NYC, 0-60 in 15 minutes is not to good. Driving like you suggested is how I got 55.6 mpg and another time 715 miles with 1.2 gallon to spare. At least with the Giles IP and newer engine, accelerating from 60 is much nicer. I already have 21k on the engine, it's been to Canada, Syracuse, State College, PA, and the VW Fathers Day show in CT. With all the hills and breaking it in, 40 was a mark I couldnt hit. With old engine, I drove to Boston for 2 firemans funerals years ago, doing 70-75+ WITH A/C on I still got 43. Keep hitting with ideas. More than welcomed. Thank you.

Stay safe, stay well. Jimmy.

[wolf_walker]

It isn't too big a leap of logic to say more fuel/power = less MPG.
Efficiency at light throttle cruise is the question I guess?

My AAZ has never got the MPG the 1.6's did(which was in the low 40's at modern road speeds),
and I've had TD and non and the AAZ has been TD and non. 
But it's a larger motor with more power, so..  ?

I still ponder it from time to time.
I had an 86 Scirocco that was bone stock in an extremely good state of tune
and it got the same combined long-term average my 1.9 in a Caddy does.
And it was faster.  Seems peculiar but neither myself of father have been able
to run down the theoretical issue inside a decade and over 100K miles that have included
new injectors and pump and tires and alignment and brakes, etc, etc.
I still ponder.  But not a lot.

Have you verified your odometer accuracy recently?

[ORCoaster]

I would say the 38 in town is going to be typical for NYC.  These engines like to be steady state not that up and down stuff the city throws at it.  Tires inflated to top PSI or just recommended PSI?  Throttle up and down like an old man and you will be rewarded.  With plenty of dirty looks from your fellow NYC friends but you will get better mileage.  Timing is key and some of the older worn out IP's do better with the increased timing.  Increased IP pressure relates to increased dynamic time so if you don't know an actual number you can measure the out flow of the IP at 1000 RPMs and you should get about 750 ml in a minute.  If you don't tap in the pressure regulator on the front of the pump.  Be careful to loosen it up first because if you drive it down too much you have to take it out, drive it all the way out and start all over from the beginning.  It is great to have a gauge on the pump but beyond some to make that work.  It is a mod of sorts. 

Temperature ok?  Cold engines use fuel.  Start cable work or not?  Compression good on all cylinders?  injectors all spray at the right bar and equally across the board?  Come to think of it the fuel itself is a variable,  2 stroked or waxed.  So many things that can change MPG.  Hard to get them all flushed out in a summers time.  Takes to much driving to change one at a time but that is what you have to do to be sure you are not changing one against the other. 

later DAS

[745 turbogreasel]

With the Giles pump, I'd assume dynamic advance is good, but another few degree  on the base timing might  help economy.

[burn_your_money]

That's a good point, have you checked the compression? Do you know how many mm of advance you are running?

[fdnyguy]

It isn't too big a leap of logic to say more fuel/power = less MPG.
Efficiency at light throttle cruise is the question I guess?

My AAZ has never got the MPG the 1.6's did(which was in the low 40's at modern road speeds),
and I've had TD and non and the AAZ has been TD and non. 
But it's a larger motor with more power, so..  ?

I still ponder it from time to time.
I had an 86 Scirocco that was bone stock in an extremely good state of tune
and it got the same combined long-term average my 1.9 in a Caddy does.
And it was faster.  Seems peculiar but neither myself of father have been able
to run down the theoretical issue inside a decade and over 100K miles that have included
new injectors and pump and tires and alignment and brakes, etc, etc.
I still ponder.  But not a lot.

Have you verified your odometer accuracy recently?

Well, Wolf. I was very much aware of the more fuel/power= less mpg. Much appreicated. But some here have posted a nice jump in MPG with the Giles IP. And FWIW, I may be wasting everyones time because I have NOT opened the air intake to its max. Was thinking about an AAZ but this 89 is like an old shoe. POS, but fun to drive. And I put a ton of miles a week on it.

As for the odometer, I think its pretty accurate using the mile makers on the roads AND used a GPS. Funny thing was it jumped 30k in 1 week. For some odd reason the 10,000 moved along with 1's. Has 245k but now reads 275. I have heard of the guy in Florida who rebuilds them, I can look into it. Scott replaced a lot for me, and the suspension and front end is preactically new.ball joints  Shafts, control arms, brakes, radiator, ball joints all done by one or another ( I used a "guru" off the TDI forum and was VERY satisfied).

Keep the ideas coming. You guys are the best.

Stay safe, stay well. Jimmy.

[fdnyguy]

That's a good point, have you checked the compression? Do you know how many mm of advance you are running?

We would have to ask Giles and Scott. They would know.

Or we (you...lol) can look it over when and if I get there.


Stay safe, stay well. Jimmy.