tips for fuel economy

[JamesBa]

Diesel-Hybrid

I don't think a diesel-hybrid will ever make it to the states, at least.

Why not?

 

[oilhammer]

Why not?

Too expensive.

And we have at least one model sold here that was available in "regular", a diesel, and a [gasoline] hybrid: the NCS Jetta sedan.

Base price: $15k

TDI option: $22k

Hybrid option: $23k

So, theoretically, the "TDI+hybrid" would be around $30k... to start. Most would get tarted up, so would you pay for a $35k Jetta while the base model was sitting right next to it that started at $15k? I certainly wouldn't.

There was a diesel hybrid E-class sedan on display at the NAIAS a few years back. It was a Euro model, not ever sold here, although we did get the 4 cyl diesel like it had for three years. No idea what it cost, but it likely was not cheap.

 

[NewTdi]

Just an update on my quest for achieving better FE. In the past I used to get very good economy before I started with all the mods; however even with the mods these cars have way better FE than 99% of other combustion cars on the road.

I have been testing the P&G method as described on the early pages of this thread. When on the freeway and I do a lot of freeway driving I use the following technique. I gently accelerate for 5 seconds and I glide for 7-10 seconds. I can achieve on a my local highways an average range between 55-60mpg however in the 3 miles that it takes me to go from the freeway exit to the front door of the office my mileage drops to 51mog. These values are measured by a ScanGauge which has a margin of error if 0.0xx gallons. When I fill up for example my ScaGauge will tell me that the fuel consumption for the tank was 12.5 gallons however when I do fill up the actual fuel pumped might be 12.55; I wish there was a way to add one more decimal value to the ScanGauge. I run the tires at 38psi.
My car is somewhat modded with a BG "S7" turbo, PP502 nozzles and RC3+ tune.
I just wanted to share my experience here. In the past (5+ years ago) I used to participate in the monthly mileage competition and 700 mile tanks were often achieved.

 

[Lightflyer1]

Driving isn't supposed to be such a chore. I am happy with the mileage I get just regular driving down the road. No way I am going to do that constantly every 15 seconds over and over again. You must want that extra economy pretty bad.

 

[NewTdi]

Driving isn't supposed to be such a chore. I am happy with the mileage I get just regular driving down the road. No way I am going to do that constantly every 15 seconds over and over again. You must want that extra economy pretty bad.

After a while it becomes second nature and to some degree I agree with you, get in the car and drive/go. Bit I am glad to get those extra 3-5mpg without much effot.

 

[Cbus27]

Upgrades for fuel economy?

Hello,

This is the first time posting anything so forgive me if it’s not correct area or not enough info. I have a 2002 Jetta ALH w/ 5 spd manual and it’s stock. It has 297k miles and the turbo is about ready to go. I’m getting High boost PSI faults so I assume the VGT is sticking on turbo. I also assume it’s leaking a little oil which is common for the mileage and age.

I will be driving 115 miles all highway one way starting this summer 5 days a week. I am currently getting 43 mpg.

I contacted KermaTDI about a new turbo they suggested VN-17, new injectors 520 and a tune. I was quoted $2k for everything I need. I told them I wasn’t looking for a lot of power over stock but an increase in mpg or at least stay with what I’m getting now.

My question has anyone do this upgrade ? What mpg gain if any did you see ? Is it worth putting $2k into a 300k car. Mechanical it’s a great car and the body is good. Interior is excellent. I will just be using it to commute. I only paid $300 for the car and have put 15k miles on it already.

Thanks in advance.

 

[Lightflyer1]

I would find the trusted mechanics list here and find someone close to you and have the car evaluated first. IDparts has a reman stock turbo for $529 if needed.

https://www.idparts.com/vnt-15-turbocharger-038253019c-reman-p-4608.html

I would skip the tune and injectors and just do a dieselpurge instead.

http://forums.tdiclub.com/showthread.php?t=87948&highlight=diesel+purge

You will never recoup the money spent for the tune and injectors from fuel savings. So don't do that unless you really need new injectors and want a tune. Stick with what is needed to run. If you can do your own work you should be able to keep it under $1k easily.

I would just keep it stock and get it in the best shape you can. You may not even need a turbo just yet. You have a number of trusted mechanics around you there.

https://www.google.com/maps/d/viewe...f96k&ll=40.316470609350816,-74.10828396875002

 

[Cbus27]

I did a Moly diesel Purge back when I purchased the car. I have a lift and my good friend and I own 6 VW’s between the 2 of us. The labor will cost me nothing and I understand I will never recoup the actual $2k investment. Just wanted to know if anybody has replaced all these ? If there are any other better options out there ? I understand KermaTDI is a good company but as with any good salesman they push their products because the are in the business to make money.

 

[Lightflyer1]

That is probably about what you should expect to spend no matter who you got this stuff from. Tune, injectors and turbo. Just from my reading here and experience.

 

[Cbus27]

Well thank you all for the replys. I have some thinking to do. I plan on keeping car till I can’t fix it anymore

 

[Cbus27]

I have another question. If I up grade just the turbo to a VN-17 and the MAP sensor will I need a tune so it doesn’t over boost since it’s a larger turbo than what is on the car already

 

[amit9]

Check/Lube the lever on the VNT actuator arm, it helped restoring some power in my case.
Refer to: https://www.myturbodiesel.com/pages/tdi-wiki/
"VNT turbo actuator adjustment and repair/replacement on TDI engine-mk4"

Bigger turbo/Injectors/Tunes are all desirable upgrades, and as Lightflyer1 said, their costs will never be recouped.

Check/Clean the EGR valve and the intake manifold. At this age and mileage, those are probably clogged. Cleaning them is not much cost assuming you're DIY, and will give you some mpg increase.
Check/Adjust the rear brake parking cables, if the wheels are not rotating freely. The MK4 rear wheels are highly prone to sticking/dragging, and will lower the mpg.
Check all vacuum lines.

Hello,

This is the first time posting anything so forgive me if it’s not correct area or not enough info. I have a 2002 Jetta ALH w/ 5 spd manual and it’s stock. It has 297k miles and the turbo is about ready to go. I’m getting High boost PSI faults so I assume the VGT is sticking on turbo. I also assume it’s leaking a little oil which is common for the mileage and age.

I will be driving 115 miles all highway one way starting this summer 5 days a week. I am currently getting 43 mpg.

I contacted KermaTDI about a new turbo they suggested VN-17, new injectors 520 and a tune. I was quoted $2k for everything I need. I told them I wasn’t looking for a lot of power over stock but an increase in mpg or at least stay with what I’m getting now.

My question has anyone do this upgrade ? What mpg gain if any did you see ? Is it worth putting $2k into a 300k car. Mechanical it’s a great car and the body is good. Interior is excellent. I will just be using it to commute. I only paid $300 for the car and have put 15k miles on it already.

Thanks in advance.

 

[jhonster]

Hey there Oilhammer. I think you’re a VW tech. Right? If so, I had a question if you didn’t mind me asking.

I’m an auto tech as well. Mostly GM, Ford, Chrysler, Honda, Toyota stuff. Lots of drivability repairs. I’m a licensed smog tech as well. My 2013 VW Jetta Sportwagen TDI refuses you get better than 22-25 MPG. Dealership just replaced the hi press fuel pump, injectors, fuel filter etc about 8 mo ago. And replaced the EGR & DPF about 4 months ago. I complained both times about the fuel mileage & they say they can’t duplicate it. They reset the Av consumption & they say they’ve gotten 38 mpg the 1st time they did repairs & 42 mpg just this last repair. 8 mo ago the car did indeed get 38 mpg when they gave it back to me after the hi press fuel pump, but...it would lose about 1/2 to 1 mpg every day or every other day driving my usual daily 25 miles to work & 25 miles back home via the freeway. Until finally the MPG got back down to 22 mpg. It’s gotten 22-25 mpg since I bought the car used almost 2 years ago now. I keep telling the dealer they’re missing something. Either the O2 sensor in moving too slow, biased in voltage, or maybe the MAF is dirty or out of calibration. At either rate, this thing is reall starting to piss me off. I’m ready to trade it in for a car that has the urea system vs this one. My buddy w/a 2015 & a tune is getting 50+ mpg w/his Jetta TDI Sportwagen. Help Obiwan!!! Lol. ?

 

[Rodmiser]

jhonster
You need a 60 min. trip about every three weeks, if not every two weeks.
Helps keeping it clean & clear, all the way 50 MPH at the low end. If not 70 MPH.

 

[DeeJay]

Newer to the TDI crowd here (had a 1.6 back in the day). I've had a 2000 Jetta GLS 5 speed with 17 inch wheels for about 4 months now. It has 200k miles on it and seems to run right (except hard starts in the cold).I have a 100 mile daily commute to work and back. It's almost all expressway. I drive spirited and use cruise anywhere from 75-85mph everyday. I average about 42 each tank. I drove quite conservative for a tank and got 50mpg. If I drive like a normal person should, I get 45mpg. There is always some city driving on every tank. Oh, and I run 50 psi in the tires for lower rolling resistance. May get some different wheels and tires to get better mpg. On the coasting...I almost always hit neutral. I can coast a mile into town on my way home in neutral, but only about 200 yards with it in gear before I have to get back into the throttle. If I want to slow down, I will leave it in gear.

 

[lennypizzas]

i switched over to bridgestone turanza serenity plus tires after the factory originals wore out, and went from 5.2L per 100km to 4.7L per 100km without having to change my driving habits...they do however use more fuel in the colder winter months and are not recomended for winter driving

 

[amritbareta]

Thanks for such helpful tips dear...........These will really help us

 

[snuggle.pants]

Now I figure its about 12.5 cents per mile if diesel is $5/gallon operation cost.
I've recently swapped in a 11mm pump into my 2000 ALH Jetta 5speed with 249,000 miles on it! The old pump was leaking from the underside and I still averaged 40mpg.
I had to reset the injection quantity. VAGCOM is a very important tool in my tuning kit. Billowing smoke on acceleration before the adjustment ( IQ was .5-1.0), after just a slight smoke (IQ 2.0) DO NOT FORGET TO SAVE THE CHANGED VALUES.
I'm glad the forum was able to help me out and appreciate all the information available here.
I installed Kerma's DLC 520 injectors a few years ago and got a power bump after tuning with the stock pump, my car has a 2.5" exhaust from the turbo back and a level 2 clutch.
My next investment will be a larger turbo I think.
Tires are super important as is alignment for superior fuel economy. I would like a panzer skid plate and all the goodies with it but they are on eternal backorder.
My wife has a 99 ALH Jetta that is stock at 250,000 miles. It is getting new injectors, clutch and timing components next.
My daughter has a 2004 BEW Jetta that is having a turbo issue she tells me, the joys of fatherhood.

 

[TDeanI]

I bought a Scan Gauge II and that was a real eye opener. After two weeks of driving with it. My gas mileage jumped 20% from just changing driving habits. I still haven't refilled the tank, (I have gone 400 miles and its still on 18 gallons) but from checking my daily mpg average I have found:

Biggest thing I could now see now with a Scan Gauge:

1. You use way more fuel accelerating than I imagined. Like getting 16 mpg while going up hills. Any boost instantly drops the instant gas mileage in the teens. Your trip mpg average drops like a rock. I used to do 65 mph - 70 mph up steep hills on the freeway because it was effortless. Now that I see what that does to my trip average mpg, I have slowed down on hills.
2. Driving in the left fast lane tailgating the car in front of you, like everyone else, is the worst way to save mpg. Constant throttle adjustments suck fuel. You can't really coast since you are too close. Coasting is where you get your biggest mpg bump.
3. At 55 or 60 mph on flat ground, I got way more mpg than I imagined. Like over 60 mpg. At a constant 55 mph its 62-63 mpg. My previous best tank before the Scan Gauge was 45.7 mpg driving at 65 mph or slower. There are huge mpg gains at 55 mph - 60 mph. I thought a few mpg, but not like a 25% increase. I wouldn't want to drive 6 hours at 55 mph, but on a 20 mile commute it only adds minutes to your commute.
4. Coasting in neutral is like 337 mpg at 60 mph. Coast down all hills and coast up to lights in neutral. It makes a big difference to your trip ave. mph. Even coasting for 5 seconds, you can see the bump on your trip average mpg.
5. Use the highest gear you can without shudder. My mpg is horrible in 2nd or 1st, like below 30 mpg at constant speed. The same speed in third gear is 50 mpg.
6. You can coast a lot without really dropping your speed by more than 5 mph, but you easily gain 10% - 20% or more better gas mileage on trips. My commute has a lot of grades, didn't realize it until I had the Scan Gauge. I now know on my route where to put it in neutral and coast.
7. I tried some Pulse and Glide on a 4 mile stretch of 45 mph zone. I averaged over 65 mpg on this going between 50 to 43 mph. This works. Takes some effort and attention.
8. Going up any kind of long hill will drop your mpg significantly but I found if you keep it at 30 mpg (instantaneous) going up the hill by slowing down, coasting down the same hill will increase your trip average significantly. So any hill is like a long pulse and glide.
9. I thought I would be holding up traffic on the freeway trying these extreme mpg trips. Nope, I stay in the right lane and still have to pass a few people. I am surprised how many people in newer cars are driving 55-60 mph. I follow commercial delivery trucks and never have to pass them.

 

[Ragdude]

Using your cruise control; is the easiest way a majority of the driving public could improve their mileage.

 

[Lightflyer1]

Add slow down. Wind resistance goes up as speed increases.

https://www.mpgforspeed.com

My old 2013 Passat SEL (pre emissions scandal) did excellent on the highway at 65 mph. 53 mpg. On cruise Austin to Wichita and back. Right up IH35 the whole way. Don't take many road trips in the Beetle. More a commuter car vs the Passat.

 

[TDeanI]

Add slow down. Wind resistance goes up as speed increases.

https://www.mpgforspeed.com

My old 2013 Passat SEL (pre emissions scandal) did excellent on the highway at 65 mph. 53 mpg. On cruise Austin to Wichita and back. Right up IH35 the whole way. Don't take many road trips in the Beetle. More a commuter car vs the Passat.

What was your mpg after it was "retuned" by the Dealer?

 

[Lightflyer1]

Didn't own it then any more.

 

[ezshift5]

Speed, wind resistance and fuel blend are all - IMHO - big MPG factors....................

My 2013 VW JSW TDI 6M - via buyback - has given way to the 1.4L EA211 (thru a manual)...............

I miss that diesel wagon - - - - but the diminutive RON 87 1.4 gets .9 of the wagon's stellar fuel numbers.


regards,


ez

 

[Rumblebunny]

Some of the these techniques are only useful in a manual. My 2002 NB is an automatic. Since I drive like Grandma (5 car lengths back, 2 mph over the highway speed limit [right lane of course]), my mileage is as high as 41 mpg. I'd like to get that up, sure, without making extreme mods. It needs front end work (lower control arms and alignment) and new LRR tires, which could gain me 2-3 mph. Shocks and struts may be needed too. Will a skid plate help at all? There isn't one now.

I like the idea of an ECO tuning (after doing all the other fixes, of course). Green Diesel Engineering is no longer in the VW business. Has someone else picked it up? I'm not interested in a power boost for speed, just one that corrects the turbo lag and power distribution. It seems like it should make adjustments to the transmission too. Again, it won't happen until all the other things are fixed, if at all. But I like to know what the options are.

 

[kjclow]

What was your mpg after it was "retuned" by the Dealer?

I know you didn't ask me but in my JSW, I could hit mid 40s mpg around 73 mph. Tank averaged out around 41 for all interstate driving. Just came back from an almost 3000 mile trip and averaged around 37 on the interstate. About 35 for the whole trip using cruise when the monsoon rains weren't too bad. So dropped a little more than 10% since the fix.

 

[kjclow]

Some of the these techniques are only useful in a manual. My 2002 NB is an automatic. Since I drive like Grandma (5 car lengths back, 2 mph over the highway speed limit [right lane of course]), my mileage is as high as 41 mpg. I'd like to get that up, sure, without making extreme mods. It needs front end work (lower control arms and alignment) and new LRR tires, which could gain me 2-3 mph. Shocks and struts may be needed too. Will a skid plate help at all? There isn't one now.

I like the idea of an ECO tuning (after doing all the other fixes, of course). Green Diesel Engineering is no longer in the VW business. Has someone else picked it up? I'm not interested in a power boost for speed, just one that corrects the turbo lag and power distribution. It seems like it should make adjustments to the transmission too. Again, it won't happen until all the other things are fixed, if at all. But I like to know what the options are.

I found Bridgestone Ecopias gave me a 2-3 mpg boost in the JSW. I'm on my second set of them now.

 

[Rumblebunny]

Which Ecopia?

 

[kjclow]

H/L 422 plus I got them from Costco

 

[BRMman]

It needs front end work (lower control arms and alignment) and new LRR tires, which could gain me 2-3 mph. Shocks and struts may be needed too. Will a skid plate help at all? There isn't one now.

Alignment alone can make a significant difference, which if the ball joints are worn, the alignment is off. The skid plate will help as well, by reduced wind resistance under car. It also helps a lot in keeping engine bay clean.