Help me understand "tuning" options if I want better fuel economy.

[4th4]

This question's been beaten to death I know, but I've been crawling these forums for about a month now and so many of the threads on this topic get derailed or hijacked so I figured I'd just phrase my own topic in the TDI 101.

I have a 2005.1 Jetta Wagon BEW with 205k miles.
The PO did an "egr delete" and egr cooler bypass. He did leave the egr in place however.
My understanding is he didn't want to remove it in case he moved to a smog inspection state (I do not live in an inspection-State so this isn't a concern for me). and the cooler pipe kept cracking on him so he installed a bypass kit.
No other mods that I'm aware of and the car runs great.
My mileage isn't horrible (approx 500 miles per tank of diesel)
PO always used whatever oil is recommended for the BEW cam-wear issue, which I will continue to use as well. I have a quart of it I just forgot the name.

I'm told a "tune" will help smooth the boost curve out a little bit (i.e. help it run better).
Will it also help with economy?
Not looking to turn this into a sports car, just want to increase my range without getting weird about driving habits (don't want to turn into a hypermiler)
The car is plenty zoomy which I like. Not interested in upgrading my clutch right now either.

Malone stage 1 or stage 1.5? What will that get me?

I'm hearing reports of folks getting 60+ MPG's with the right mods. Is it realistic to think a "tune" will increase mileage?


Thank you!

 

[Mongler98]

I'm not sure what threads you're referring too.
Mpg is all about driving behavior.
Making more power with what you have.
Very common topic every time fuel goes up a penny!
Best bang for your buck is a scangauge II and learn how to drive accordingly

 

[Lightflyer1]

Those getting 60+ mpg are either doing all highway cruising and driving just for that or aren't being truthful or some of both. The vast majority of people don't report that kind of mileage, tune or no tune (or mods). Most people who do mods for this never recover the mod cost through cost savings in fuel. As Mongler98 pointed out how you drive is the most important factor in fuel economy and it is free. A car that is in excellent mechanical condition is all that is required, really. Getting a tune and not changing your driving habits for fuel economy will more than likely result in the use of more fuel. Most people want to use the new found power the tune produces and miss out on the economy part of it altogether. There is no magic bullet. A tune and equipment will help some if you drive right, but will probably never pay for themselves and I doubt you will ever see anything close to 60 mpg no matter what you do. Best I ever got in my Jetta BRM was 53 mpg one time all Interstate, nonstop at around 65 mph or so the whole way (806 miles). This was just a test trip to see what could be done with them when they were new. I had a Rocketchip tune and a few other minor mods too. There were some people in the ALH cars that were able to get better mileage, not in the PD cars though that I have seen.

 

[Mongler98]

stage 6 tune, 32psi, stock internals lightly ported head, gt2052, 764's and a bunch of fun bits.
average grandma driving 50/50 about 39 mpg compared to the normal 45 i would get stock and the 48 i got with just the nozzles.
did full highway non stop drafting behind a truck for a long time (80% of the time) got 62mpg.
i could get a reliable 52mpg if i did just highway at 65ishmph.
point is that its not the build, its how you drive it. i would get literally 8mpg on my even days including the 1 hour each way travel because race car. poor AHU.

you can put whatever tires you want, do all kinds of crazy stuff and go crazy on chasing that MPG average... but if you suck at driving it for good economy its pointless. I can get any car you give me and get an extra 3mpg average just by driving smart.
pretend you have no brakes and there is an egg under your pedal.
you do know that the speed limit is the LIMIT, not the recommended go faster than this right? want good mileage, slow down so you don't have to speed up.
these threads derail because we have all heard it all before. Its kind of pointless to talk about it.
want to save some $, take the bus!

 

[burpod]

well tuned you can definitely get 50+ mpg driving normally without trying, if all hardware is good. i could get 55mpg without trying too hard in my mk3 (self tuned) with vnt 1856 11mm pump and .260 nozzles. i did have 195/65/15 tires and a .681 5th gear. that's keeping highway speeds to 70-80mph, but also some regular around town driving just not beating on it too much. what you get from your average big-name tune might not always be as good as some say..... there is vast room for improvement there.

i agree how you drive is a big part of it, but the tune (and hardware to some extent) can make a *huge* difference.... the level of tuning people seem to be happy with for the TDI is a little disappointing :/

 

[Lightflyer1]

As I said before the PD cars (OP has a BEW, claimed) have never shown those kinds of mpg from my reading and experience. The ALH and older cars have shown some of this. Show me any evidence that a PD (BEW or BRM) has gotten these kinds of mileage results. Then show me the cost comparisons between the money spent on tunes and equipment vs the money saved on fuel. The only claims I have seen is from people who drove a few miles putting around in high gear and minimum revs and claiming great increases in economy. Even the professionals don't get that without trying very, very hard. Injectors and other parts for the PD engines are way more expensive than the ALH engine cars.

Couple attempts around-U.S. mpg record in 2009 VW Jetta TDI

Husband and wife team John and Helen Taylor struck out from Chantilly, Virginia today on a 23-day, 8000 mile loop around the 48 contiguous states in an attempt to break the Guiness World Record for the lowest fuel consumption on a trip around the U.S.

www.motortrend.com

.

Helen and John Taylor reset fuel mileage world record at 67.9 mpg - Autoblog

Helen and John Taylor have done it again. The husband and wife team of hyper-milers fuel stretchers have just broken their own "48 Contiguous U.S. States Fuel Economy Guinness World Record" with an average of 67.9 miles per gallon. That's quite a bit better than the duo's previous record of just...

www.autoblog.com

 

[burpod]

back years when i was daily driving my 05 BEW jetta with a 17/22 and rocketchip tune (and .658 5th), i routinely got 50+ mpg without much ado. i tried a couple tanks keeping speeds down to actual speed limit and got 60mpg. doing my own tuning now, i don't doubt i could possibly do a little better. i've started tuning my wifes 06 BEW golf, but it unfortunately has the 5spd regular jatco automatic. with it's previous tune it seemed to average 40-42 for the driving it sees, which is moderate 40mi round trip commutes and around-town driving and occaisonal day cruises out on the higway more. on a past road trip, it seemed to get about 39mpg doing 80mph.

of course, i'm not talking about winter-fuel cold temp driving.

 

[Lightflyer1]

here are the Fuelly stats:

2005 Volkswagen Jetta MPG - Actual MPG from 43 2005 Volkswagen Jetta owners

The most accurate 2005 Volkswagen Jettas MPG estimates based on real world results of 2.1 million miles driven in 43 Volkswagen Jettas

www.fuelly.com

You would be one of the outliers on the right. Like I said few people get that kind of economy and it almost never pays for itself.

I don't see any improvements that would increase their economy from around 33 mpg that was stated (indirectly 500/15) to over 60 mpg.

 

[burpod]

i've never used fuelly, or really trust it as a good data source. but from my years of experience driving a couple BEWs, if it's a manual transmission with semi-normal conditions and you're not getting 45+ mpg somethings wrong with your hardware, tune, or are a terrible driver perhaps in areas of extreme heat like TX has in the summer, constant AC use and/or very crappy driving conditions i would expect worse mpg, but in more temperate climates with normal AC use i wouldn't expect anything less

 

[Lightflyer1]

Well it is in the OP's court now. Both sides have been discussed. Let us know what you do or don't decide to do and if you do go ahead let us know how you fare in this endeavor. Good luck!

 

[nicklockard]

Restore your EGR to full factory-level OEM functioning. It's killing your winter FE in the PNW. I know. Been there, done that. It's costing you at least 3-8 mpg in winter. Stupid stupid stupid.

Next, detune your right foot.

A tune will improve fun factor and will typically HELP fuel economy a bit as long as you don't use too much fun juice all the time. But a right-foot retune will do far more. Also, give it an Italian tuneup once a month. It really helps clear out the snot.

 

[burpod]

EGR delete doesn't kill winter FE if tune is done right. hasn't ever harmed mine..... just sayin'

 

[nicklockard]

I guarantee if you get granular enough to build a spreadsheet like I did, it does. It dramatically increased warmup times in cool weather. That costs FE, Might not matter if all you do is mostly longish drives, but for the other 80% of people, it's a freaking huge effect.

 

[burpod]

that may be your experience with whatever tunes/factory maps you have had i do plenty of around town driving and short trips as i don't have a commute...do my own tuning now, never been happier... i am no longer happy with what i previously had. in fact, i feel very disappointed with what i had, knowing what i know now, and i've had my fair share of other big name tunes

 

[Lightflyer1]

So now the OP has to write and program their own tune? If the majors won't get it there what other choice is there?

 

[STDOUBT]

burpod,
If you're as big of a codemonkey as you seem, how about starting up a mail-order ECU business!?

what you get from your average big-name tune might not always be as good as some say..... there is vast room for improvement there.

Knowing software like I do, this statement has a very truth-y ring to it.
For the less sophisticated among us, just making sure your brakes aren't dragging can net a huge improvement.
The big FE thread:

tips for fuel economy

I've put this together in an effort to help some folks diagnose what may be a loss of fuel economy (MPGs) with their TDIs. Keep in mind, many of these items can work against your car in concert to add up to a sizeable increase in fuel consumption over time, so please don't dismiss any one item...

forums.tdiclub.com

 

[burpod]

burpod,
If you're as big of a codemonkey as you seem, how about starting up a mail-order ECU business!?

Knowing software like I do, this statement has a very truth-y ring to it.
For the less sophisticated among us, just making sure your brakes aren't dragging can net a huge improvement.

oh, i've been quite busy lately been working on some stuff ....

 

[scooperhsd]

This question's been beaten to death I know, but I've been crawling these forums for about a month now and so many of the threads on this topic get derailed or hijacked so I figured I'd just phrase my own topic in the TDI 101.

I have a 2005.1 Jetta Wagon BEW with 205k miles.
The PO did an "egr delete" and egr cooler bypass. He did leave the egr in place however.
My understanding is he didn't want to remove it in case he moved to a smog inspection state (I do not live in an inspection-State so this isn't a concern for me). and the cooler pipe kept cracking on him so he installed a bypass kit.
No other mods that I'm aware of and the car runs great.
My mileage isn't horrible (approx 500 miles per tank of diesel)
PO always used whatever oil is recommended for the BEW cam-wear issue, which I will continue to use as well. I have a quart of it I just forgot the name.

I'm told a "tune" will help smooth the boost curve out a little bit (i.e. help it run better).
Will it also help with economy?
Not looking to turn this into a sports car, just want to increase my range without getting weird about driving habits (don't want to turn into a hypermiler)
The car is plenty zoomy which I like. Not interested in upgrading my clutch right now either.

Malone stage 1 or stage 1.5? What will that get me?

I'm hearing reports of folks getting 60+ MPG's with the right mods. Is it realistic to think a "tune" will increase mileage?


Thank you!

Hey genius - how can we tell what your MPG is without knowing the size of your tank ? 500 miles for a tank could mean anything from 10 MPG to 60 (or more) MPG.

 

[Mongler98]

Hey genius - how can we tell what your MPG is without knowing the size of your tank ? 500 miles for a tank could mean anything from 10 MPG to 60 (or more) MPG.

Hey Genius.... since ALL VW 2005 makes have a 14.5 gallon tank... i did not think he needed to state that.
But if you don't believe me and you never do....
https://fueltankcap.com/volkswagen/jetta/2005

500/14.5 = 34 mpg... not terrible for the waggon but still crap for a TDI and thus why every week we have a "how can i get better MPG"

 

[JELLOWSUBMARINE]

Aside from MPG...

My reason for a kerma non delete tune was to save my DPF (2011 JSW cjaa). MPG... didn't see much difference. Was it worth it? Yes but really only for long term health of my over smogged engine. The dieselgate emissions overkill retuned CPO is now "normal" and MUCH better on the ultra expensive smog components.

Since your BEW doesn't have the same issues and you are in a no smog area you still can benefit the engine life and performance with a good tune

 

[4th4]

Hey Thanks for all the feedback (from both sides).
To be clear, I never expected a Tune to be the secret sauce for better MPG's. I realize driving habits, terrain, etc is the main contributor.

That said, I'm new to diesels & TDI's (not new to wrenching on my own things or researching things out of my wheelhouse) and as someone from the outside looking in we hear about these high-mileage super-stories associated to the word "TDI" promptly followed by "Tune" and "Egr delete", etc. So it creates a bit of a rabbit hole into another dimension.

If the car runs better with a tune, it leads me to believe it may improve mileage as a side affect, but not the other way around.

I'm not a lead foot, and have no desire to do much else to this car other than something easy or plug-n-playable like a reflashed ecu. So weighing the benefits of a tune is step one.
Part of why I posted in the 101 section.

Thanks again.

 

[nicklockard]

Many tunes do in fact increase fuel economy at the expense of slightly more NOx emissions. When requesting a tune, let them know your desired attributes & goals.

 

[Mongler98]

Many tunes do in fact increase fuel economy at the expense of slightly more NOx emissions. When requesting a tune, let them know your desired attributes & goals.

and thus why its illegal to do so and keep road tags on it ... by altering an emisisons device...
depending on where you are it could be impossible to pass emisisons once tuned.....

 

[Lightflyer1]

Something simple would be just a tune without tampering with any emissions equipment. It is possible to get a mileage improvement if you drive right and your car is in good shape (It needs to be in shape before the tune). But I wouldn't expect too much if any. If you notice the web sights all quote power increases without much claim to economy. Calculate how long it would take to pay for the tune. If that number is acceptable to you then go for it! The extra power is nice but you are looking for economy it seems. Best bet is to talk to the tuner you want to use.

 

[Mongler98]

the simpolist is the advice i gave at first. scangauge II and learn to drive better.

 

[Lightflyer1]

the simpolist is the advice i gave at first. scangauge II and learn to drive better.

I think the OP knows that by now. But they are asking about a tune.

 

[Mongler98]

I believe that learning how to drive better is a better tune, of your mind!

 

[Lightflyer1]

Maybe be but that's not the topic and has been covered already.

 

[ToxicDoc]

Hey Thanks for all the feedback (from both sides).
To be clear, I never expected a Tune to be the secret sauce for better MPG's. I realize driving habits, terrain, etc is the main contributor.

That said, I'm new to diesels & TDI's (not new to wrenching on my own things or researching things out of my wheelhouse) and as someone from the outside looking in we hear about these high-mileage super-stories associated to the word "TDI" promptly followed by "Tune" and "Egr delete", etc. So it creates a bit of a rabbit hole into another dimension.

If the car runs better with a tune, it leads me to believe it may improve mileage as a side affect, but not the other way around.

I'm not a lead foot, and have no desire to do much else to this car other than something easy or plug-n-playable like a reflashed ecu. So weighing the benefits of a tune is step one.
Part of why I posted in the 101 section.

Thanks again.

You can definitely tune for better mileage. If your injector tips are worn or dirty, cleaning them would help too. On my ALH even a stage 1 tune radically enhanced the drivability of my car. I found it much smoother driving with more power, not massive but noticeable. Take offs from a stop became much easier, no hesitation or dip in rpm risking a stall. I'd recommend one regardless of mileage improvement or not.

 

[jokila]

Does your car have the ventectomy mod? On the mk4s you can remove the vent nipple permanently and get another 2 gallons to the tank.

While this doesn't improve MPG, it will extend your range on average about double the MPG number in distance.