MKIV-Will Injector balance net better MPG

Debating weather or not to send out injectors for balancing or these other set up options.

Car is a 2003 Jetta Wagon with VNT-17 and stage 4 tune with PP520's, full exhaust, upgraded i/c, etc. I am only getting 40mpg or so and my commute is increasing. I was thinking that an injector balance might net me some better MPGs.

Any opinions? I know a lot of people are getting mid 40s with a similar set up. Usually on the highway I am rolling at 78 with the cruise control.

Thanks for any info.

??? 40's, yea its your driving. Try and get a used scangauge II and run with it for a few months and i guarantee you will see a 5mpg boost, JUST from better driving habbits for mileage. Being able to see your MPG in real time and GPH is incredibly helpful.

Aside from that, those 520's are way to big for that tiny turbo. im running a gt2052 monster with 764's and im getting 58mpg average driving 80mph and a decent amount of city too. When i go all highway on a trip, i reliably get into the 63-65mpg but that's cruise control at 65mph and i usually try and draft from trucks.

bet bigger turbo or smaller nozzles. and learn some better hyper mileage habbits. you should easily get 45mpg with that set up, 48-50 if you get some skills on knowing how to hyper that mileage all up in here!

I know my injectors are smaller but i have a custom stage 6 tune from malone and smoke the heck out of traffic.

Thanks. I almost never see smoke and rarely have it at full throttle for any length of time. I thought the 764's were bigger than the 520's. Am I mistaken? I know a lot of people here are well in the mid 40s, but 40 seems to be all I get.

Would adjusting the IQ down help me? Again, I rarely see anything other than a light haze and believe my IQ is around 5-6.

Who did the tune?

PP520s aren't too big with a stock pump and a VNT-17 on an ALH. Common setup. But it depends on the tune (and the tuner).

40 MPG isn't horrible, but it's not great. I just filled my wagon tonight (PP357s with an 11mm pump and stock turbo, RC3+) and got 46.8. And I typically drive 75-80 on the highway. I'm in MA so weather is pretty similar.

I'd look at how the car is set up. Make sure static timing is perfect, and that timing is advanced (65-70 in VCDS Basic Settings block 2). You may want to advance the timing a bit in VCDS as well, but ask your tuner about that. These little things all add up.

You should also run some logs and make sure your turbo is responding to boost requests correctly. And look at injector balance. If it's way off you may want to send them out, but if not I'd work on other things first. Also look at MAF function. Sometimes MAFs do a slow fade and affect performance in minor ways, but the car seems to drive fine.

Monglers 2052 is hardly worth calling a monster. Its only just a bit larger than a vnt-17. And mongler is mistaken not you, your p520's are far from too large, only .216 nozzles vs .232 for the 764's. But he is right with the driving habits.

Letting yourself coast earlier before stopping, not playing bungee with the car in front of you ect definitely has a measurable difference for me. We are also just coming out of winter so you've been running winter diesel which will knock off a few mpg and idling to warm up just kills my mpg I find. Letting my car run for 5-10 minutes will knock a solid 50-100km off my tank. With stock hardware and a tune I will see between 42 and 55mpg depending on the time of year and how I drive. Doing 80 on the highway I only get 42mpg as well so it wouldn't seem your doing too bad.

I'd say do a tune up with timing iq ect and try driving nicer and see what happens first.

EDIT: IDB got to you first...

Turbodude1 said:

Debating weather or not to send out injectors for balancing or these other set up options.
Car is a 2003 Jetta Wagon with VNT-17 and stage 4 tune with PP520's, full exhaust, upgraded i/c, etc. I am only getting 40mpg or so and my commute is increasing. I was thinking that an injector balance might net me some better MPGs.
Any opinions? I know a lot of people are getting mid 40s with a similar set up. Usually on the highway I am rolling at 78 with the cruise control.
Thanks for any info.

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The decision to send them out would depend on whether they were set up right to begin with,
how many miles are on them and if they are DLC's or not.
Plain Jane PP520's may only stay tight for 100,000 mi or so but DBW gives a 5-year,
unlimited mile warranty on the DLC's.

Oh yeah, have you checked your rear calipers to see if they could be dragging?

Thank you all. All very good points.

To respond to some of the ideas posted, it's a Malone tune, static timing is good and I have advanced it to the top of the green area, MAF, turbo, and nozzles have probably 20k on them. I installed the injectors and the balance is all within .4. The rear calipers are free.

I always got mid to upper 40s in my TDI Golf with RC2. Not sure why the 5 mpg decrease in the wagon, as I don't drive agressively that much. Thanks for all your ideas.

You might have Malone give you a different tune, perhaps Stage 3. I know that RC Stage 4 fueled heavy and FE took a hit. Jeff now has a 4+ (25 PSI) that fuels less and when I ran that my FE improved.

IndigoBlueWagon said:

You might have Malone give you a different tune, perhaps Stage 3. I know that RC Stage 4 fueled heavy and FE took a hit. Jeff now has a 4+ (25 PSI) that fuels less and when I ran that my FE improved.

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Hmm, this sounds interesting... Have you driven this set up? (Also on the old Golf I only had the sprint injectors. The power plus should have had a more efficient spray pattern, correct?)

I think you find something similar in that Stage III is the sweet spot for daily driving.... Quick response, enough power, and good mileage.

That's why I went back to a VNT-15 and RC3+. It's excellent for daily driving, and still makes plenty of power for street use.

IndigoBlueWagon said:

You might have Malone give you a different tune, perhaps Stage 3. I know that RC Stage 4 fueled heavy and FE took a hit. Jeff now has a 4+ (25 PSI) that fuels less and when I ran that my FE improved.

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I remember reading NevadaTDI had a retune and picked up a few mpg with a similar setup as OP. They opened the vanes more at cruising rpm/fueling if I remember right and I think decreased fueling slightly. I know for me personally I have a turbo back straight pipe and I set my tune to keep the vanes open much more than stock when cruising and results in less boost. I got two 49 mpg tanks in Texas last month which is the highest full tanks I have had since owning my 03. I just made those tune changes about 2 months ago.

h4vok said:

I remember reading NevadaTDI had a retune and picked up a few mpg with a similar setup as OP. They opened the vanes more at cruising rpm/fueling if I remember right and I think decreased fueling slightly. I know for me personally I have a turbo back straight pipe and I set my tune to keep the vanes open much more than stock when cruising and results in less boost. I got two 49 mpg tanks in Texas last month which is the highest full tanks I have had since owning my 03. I just made those tune changes about 2 months ago.

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This is interesting. The only way I am going to get 49 mpg currently is to drive down a hill for a whole tank. I do have 2.5" turbo back with no cat, so there is no restriction there.

I found switching to Ecopia tires gave me about 4mpg. What are you running? Also, what's your commute like? What size wheels? Stop and start driving on 17s is a bad combo.

210k miles, RC3, "Sprint" 520s, and almost all highway, I average 47. Nozzles have somewhere around 120K on them.

Gothmolly said:

I found switching to Ecopia tires gave me about 4mpg. What are you running? Also, what's your commute like? What size wheels? Stop and start driving on 17s is a bad combo.

210k miles, RC3, "Sprint" 520s, and almost all highway, I average 47. Nozzles have somewhere around 120K on them.

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I have OEM 15s with Ecopias, DLC520, turbo back straight pipe and a tune that I have mostly made. My n75 and requested boost have been lowered for less boost in under 25mg iq area.

Exenos said:

Monglers 2052 is hardly worth calling a monster. Its only just a bit larger than a vnt-17. And mongler is mistaken not you, your p520's are far from too large, only .216 nozzles vs .232 for the 764's. But he is right with the driving habits.

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Yes, your right about the orifice size on the nozzles, my mistake on the wording, I was trying to show that even with my larger than his nozzles and a nuts to butts tune, I get easily +15mpg than he is.
The vnt 17 almost the same size? I think not, there is a significant difference, for one running at 32psi vs 25 or whatever the max flow on the 17 is, also EGT management, the EGTs on my build climb very fast and easily can reach 1600+F without thinking about it, I would melt the CRAP out of that tiny 17.
The gt2052 is not a monster turbo by any means but compared to what these engines like, mine is a monster, that’s not nesasarly a good thing too. I have almost no boost until I get to 2600-2700 rpm's. Vs the 17 spools up almost immediately.

Tires hard 195 65 15 hankook ipike winters for now. 17's in the summer with falken tires.

Would a taller 5th gear help on the highway?

The gt2052 is not a monster turbo by any means but compared to what these engines like, mine is a monster, that’s not nesasarly a good thing too. I have almost no boost until I get to 2600-2700 rpm's. Vs the 17 spools up almost immediately.[/QUOTE]

I'm assuming the gt2052 is a fixed geometry turbo with such lag? I'm running a gtb2260 and boost comes on just a touch later than stock I believe. I've put race 520s in with the stock turbo just cuz, then a gtb1756 (210hp on the rollers), now a gtb2260. Haven't dyno'd yet but my FE went up little by little with as the turbos got bigger. I get 39 mpg almost across the board, mostly country driving like a jerk.

Something is wrong...if it isnt driving style(and I suspect it isnt as you get better mileage on the other cars) then there is something awry with the car. As a for instance, MY 03 wagon only gets 40 MPG in regular driving. And thats with a 6 Speed(ouch!). However, between custom nozzles and pump, a 2265 turbo and a ton of internal engine modifications...added to that winter tires 16 inch (blizzaks)at about 40, summer tires 18 inch (pilot supersports)....you should get waaaaay better mileage. Now, with either of my setups, I can get 46 or so...but big turbos like fuel...so it isnt as easy. Your 17 with pp520 setup and 5 speed is good for 48-59 MPG as measured on my own cars with the same mods as you.Clearly you are looking for the problem, which is good, however, I would look at the engine itself to be sure nothing is awry...and switch tunes at least temporarily to see if that tune is just too much for your style.

Thanks Mr Chill. You confirmed what I was worried about. I'll check injector balance and timing again.

All good stuff has been mentioned here; it always seems to be the little things that have the biggest effect. In that I mean the combination of the little things: tire size and type, tire pressure, and driving style just to start the list. It was mentioned getting a Scan Gauge; for me a boost gauge is a very effective "minimize throttle" notifier and Torque (or Torque Pro) with the free MPG calculator may not be accurate numbers wise (it does read high MPG) the instant MPG reading is very sensitive to throttle position.

This is what you can see when mrchill sets up your car:

Took this photo just now. This tank is all commuting and short trips, including a drive to the airport where the last 10 miles took nearly an hour. I haven't had sub-700 mile tank in years.

I never go above 500 miles. Perhaps I should book some time with him. How much fuel are you putting in?

If I fill just when the low fuel light comes on I add 15.4 gallons. Most I've ever added is 16.9. I was a little worried.

So you guys are 'venting'?

But your mileage is indeed impressive.

Yes, always.

Braggart! Clown! j/k IBW, I would really enjoy mileage like you are getting; with a VNT-15, .205's and a Stage 3 tune I used to get 52 MPG at 72 MPH. The .230's I am currently running are killing my FE; I have a set of .216's on the way to see if my FE will improve. If not I may need to change tuners... ;(

The ALH's ability to get good FE regardless of conditions (traffic, temperature) is very impressive. And when 700+ mile tanks get routine it's very hard to give them up. This setup hits a sweet spot in power and FE: 11mm pump, PP357s, VNT-15, RC3+. I think the PD150 intake manifold and airbox to intake, along with the 2.5" exhaust, help. Whatever it is, I'm going to stay with it as long as I can!

I have gotten 60 MPG tanks with mine, but I rarely have the patience to drive that slow for that long. I'll take 50 and driving normal to fast instead.

The ALH+manual is the poster child for the TDIs, because while they are all pretty frugal regardless of how you drive them, these take the cake. No hypermiling nonsense necessary.

Jeff from Rocket Chip, your PM box is full I would like to contact you, please PM me.
Or would someone else please forward me Jeff's number?