tips for fuel economy

thsheet said:

I wonder if anybody here has data on better feel consumption using a K&N Air filter?
Thanks
Thesheet

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Can the mods please purge this post from my thread?

Wow I'm posting this from an iPhone I can barely even read my own text so sorry I didn't see your rules of thread I've got nothing but hassled every post is made on this form I'm out of here and I did not think the hassles were legitimate and the other posts

Have a good life

thsheet said:

Wow I'm posting this from an iPhone I can barely even read my own text so sorry I didn't see your rules of thread I've got nothing but hassled every post is made on this form I'm out of here and I did not think the hassles were legitimate and the other posts
Have a good life

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Been a sticky for 3 years:

http://forums.tdiclub.com/showthread.php?t=290373

After going through this and a few other fuel economy threads, I'm stumped. I've got properly inflated tires (~40 psi), the wheels spin freely when jacked up so I don't think a brake's dragging, both the air and fuel filters are new this month, I even gave it a dose of injector cleaner juice… but my mileage continues to plummet. I've averaged right at 46 mpg for the life of my car (05 Golf, 308k miles, manual trans.) but since March it's been an almost steady decline; I haven't seen anything over 44 mpg since April!

I know my parking brake cable is swollen but the calipers don't appear to be dragging as far as I can tell. The rear wheels seem to spin as freely as ever. Could a brake touching really suck away 6+ mpg?

The only thing that has been done in that time period was rear struts and a tie rod end on the front of the car. I don't think those could affect anything but it never hurts to ask.

Power seems the same, idle is fine, I rarely get any smoke… Frankly, I'm a loss for possibilities. Anyone have any suggestions? The nearest trusted mechanic is well over 3 hours away with "tourist traffic" in effect for the rest of the summer so I can't just pop in and have a set of trained eyes take a gander unless I know I'm gonna be there for a while.

Tom Servo said:

...
I know my parking brake cable is swollen but the calipers don't appear to be dragging as far as I can tell. The rear wheels seem to spin as freely as ever. Could a brake touching really suck away 6+ mpg?

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Yes, but given that your rear wheel still seems to spin OK it suggests otherwise. However if your brake cable looks dodgy it is still a good idea to replace it regardless of mpg changes.

The only thing that has been done in that time period was rear struts and a tie rod end on the front of the car. I don't think those could affect anything but it never hurts to ask.
...

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Could either your front or rear alignment/tracking/etc have been knocked out by that work? If so, then perhaps your tyres are scrubbing as a result (which would also result an mpg drop). Find a place local to you which does a 'full geometry check' (not just a 2-wheel alignment).

MikeMars said:

Yes, but given that your rear wheel still seems to spin OK it suggests otherwise. However if your brake cable looks dodgy it is still a good idea to replace it regardless of mpg changes.
Could either your front or rear alignment/tracking/etc have been knocked out by that work? If so, then perhaps your tyres are scrubbing as a result (which would also result an mpg drop). Find a place local to you which does a 'full geometry check' (not just a 2-wheel alignment).

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Replacing the parking brake cable is definitely on the agenda.

The tires… that's a story in itself. I bought them at the start of the year at a local chain and it took them three tries to get the alignment right. In one case, I waited hours only to discover the kid doing the work had never done a four wheel alignment before and had never done a VW before. The best I got from them was a reasonably straight tracking but a cocked steering wheel.

Since there was some front end noise that the new tires didn't fix, the only other place I felt comfortable going was the deal over in the next state. They replaced a tie rod end and noted that the tires were already cupped after just a few hundred miles. The alignment done there seemed to do the trick — the cupping has gradually worn-in evenly across the front tires and the car tracks straight. It's honestly the first time in 8 years that I've gotten a car back with the alignment right the first time from someone. Dunno why it's so difficult for local garages to do it, but I guess my elation that the dealer "did it right the first time" may now be unwarranted.

Tom Servo said:

Replacing the parking brake cable is definitely on the agenda.

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Try feeling the front & rear wheel-nuts after a long drive. The fronts should be warm and the rears cold. If either is very hot then you have something dragging (brakes, wheel bearing, or whatever).

... but I guess my elation that the dealer "did it right the first time" may now be unwarranted.

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Well, it was just a suggestion so don't panic yet LOL. It is a common problem to find after going to a tyre place, they aren't particularly good at setting alignment (after all, if the tyres wear quickly it is to their benefit). The place that I use to do a geometry check / 4-wheel alignment doesn't sell tyres (they are a tuning house specialising in VW-group cars). They're only 2 hours away from me so not as far as your dealer.

MikeMars said:

Try feeling the front & rear wheel-nuts after a long drive. The fronts should be warm and the rears cold. If either is very hot then you have something dragging (brakes, wheel bearing, or whatever).

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It's 35°C here with 89% humidity. The rears are very hot and the fronts are scorching hot.

Tom Servo said:

It's 35°C here with 89% humidity. The rears are very hot and the fronts are scorching hot.

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Hmmm well, if the rears are hotter than 38 or so (+3c), or the fronts are hotter than about 45 (+ 10c), then I think you potentially have a problem with binding brakes or wheel bearings. The rears should be a tiny higher than the ambient temperature. The fronts will be a bit hotter due to heat from the brakes & engine-heat transmitted through the transmission, but 'scorching' sounds too hot for that.

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There is also the heating effect of direct sunlight of course. What are the wheel-nut temperatures like after a long drive when the sun isn't out?

MikeMars said:

Hmmm well, if the rears are hotter than 38 or so (+3c), or the fronts are hotter than about 45 (+ 10c), then I think you potentially have a problem with binding brakes or wheel bearings. The rears should be a tiny higher than the ambient temperature. The fronts will be a bit hotter due to heat from the brakes & engine-heat transmitted through the transmission, but 'scorching' sounds too hot for that.

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There is also the heating effect of direct sunlight of course. What are the wheel-nut temperatures like after a long drive when the sun isn't out?

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Today was a little more moderate, temperature wise, so I got down and actually spent some time with a second person, spinning the wheels and feeling things. Nothing's hotter than it should be, all wheels turn freely, but the right front does have a little gear whine which I assume is due to it being coupled to the transmission.

Looks like it's time to turn attention to the engine.

Billion003 said:

I keep all the excess trunk netting and "stuff" out of my car. Also, no one ever rides in my back seat. I'm looking to take the back seat head rests out.

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I took my back seat out since I just drive to work and back.

Crap. On track for 2 consecutive tanks at 4.7 l/100 (50 mpg) and got stuck in a 2 hour parking lot on the 401/400 on the way home last night. Brought me down to 5.2 (45 mpg) for the tank.

So, here's the tip. Check the traffic reports on your route before you start out. It can save you time, improve your fuel economy and reduce the wear and tear on the TDI. Therefore it can save you money.

The OP mentioned that he drives in 4th gear before entering the highway. I'm wondering if I can drive my 09A in 4th using the tip-tronic mode which I use mostly now adays both for up and down shifting. Would this harm the transmission in any way?

A good tip would be to run 5 gallons at a full up. I think that would light up about 80 pounds.

JB05 said:

The OP mentioned that he drives in 4th gear before entering the highway. I'm wondering if I can drive my 09A in 4th using the tip-tronic mode which I use mostly now adays both for up and down shifting. Would this harm the transmission in any way?

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I do that with both my manual 5sp Golf and my automatic 5sp Passat.

I just bought a 2014 jetta sportwagen TDI (6 speed manual). My first tank od gas I only got 30mpg. Hoping it's going to get better (like 40mpg). Any imput?

Well, I tried the pulse and glide technique and must say I'm very pleased with the result.

I'm in the UK (England) and have a 2004 Passat Highline Estate (Wagon for you lot over the pond) with a 1.9 PD TDI engine, the engine code is AWX and it makes 130hp and 285nm of torque from the factory. It has a 5 speed manual box and runs on 16" wheels with 205 wide tyres (LOL tires for you lot over the pond..... and the spell-checker).

On my work to home journey, the best I've ever got was 60.2 mpg imperial (50.12 US) and that was with light traffic, the moon an planets in perfect alignment, all green traffic lights and probably the wind blowing in the right direction.

This evening I got 64.4 mpg imperial (53.6 US) using pulse and glide. The traffic was quite heavy and I was limited as to where I could do it. Astonished. I reckon I could see 70mpg out of the old tank in the same conditions as my best previous run.

One thing that does concern me is what P&G could do to the clutch and duel mass flywheel. Even on this single journey I quickly adopted rev matching the engine speed to as close as I reasonably guess would be normal when I re-engaged power.

Very pleased.

...Oh and this is the first time I've logged in here since the 8th of August 2008, why so long away, I don't know.

Okay, Im fairly new to the TDI world, 2004 Jetta that I bought stock, used from an older gentleman in 2013 with 38XXX miles on it. Clean carfax, Clean VIN...almost too good to be true. Well here it is June 2014 and almost 15XXX miles later Ive noticed when Im cruising down the highway, ~65-70mph its taching ~2-2.5. Ive thought about talking to transmission guy about putting a different 4th and 5th gear in it to maybe lower that tach and increase fuel mileage. Im looking for some experienced guys thoughts on this. Also if you have done it please let me know prices if you can... Thanks a ton you guys....and gals

Opinions will vary. From what I've read, taller 5th gears are worth ~1-1.5 mpg improvement.
2 years ago I bought Bridgestone Ecopia tires. I gained ~3mpg.
About the same time I bought a Malone stage ii tune. That gained ~3mpg.
In the summer I average 47mpg. In the winter I average 50.5 The difference for me, is heavy A.C. use in the summer. And, I am heavy on the throttle.

Tony
Sent from my e-diesel fleet

Nice, thanks


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Great reading.

I agree with the mixed (easy/spirited) driving to give the TDI a taste of both worlds... and the DSG craves shifting through the first few gears with pace!

1/4 tank has been drunk by the car, already achieved 165 miles... look/sounds promising so far
165 miles on my GTI would have left me at less than half the tank, which the bottom half is even less in volume!

tridogg5250 said:

I just bought a 2014 jetta sportwagen TDI (6 speed manual). My first tank od gas I only got 30mpg. Hoping it's going to get better (like 40mpg). Any imput?

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Usually a brand new engine mpg isn't that great for some strange reason. After a few thousand miles you should start seeing increase in economy. Were the 30mpg combined or strictly streets or highway?

You are a godsend. You have addressed the major concern I have with my 2006 Beetle TDI (97,000 miles, original transmission). I get an average of 31 MPG which is absolutely lousy. Before reading your tips I was considering replacing the glow plugs. Now I can look at less expensive and easier fixes. Should I trust my local dealer to do the right thing or find an outside mechanic?

Is there an easy way to test whether or not the alignment is good or not. I am beginning to suspect that the alignment going out has something to do with my less than stellar fuel economy. The last time it was at the dealer's, they suggested that my front swing arms were showing wear and should be replaced. Also, before I replaced them, the rear tires were showing a curious wear imbalance on the inside of their tracks. How does one test alignment anyway?

I'm curious how these fuel economy claims are calculated. I've never been a fan of using the odometer. It seems a GPS is more accurate. When cross-checked with mapping websites and software, the GPS indicated distance is always closer than the odometer. Of course, this being confirmed over several fuel tanks documented on an Excel spreadsheet.

Interestingly, my 2011 JSW indicated mileage on the dash is very close to what I've been calculating with GPS distance divided by amount of fuel indicated on the receipt. At first, I was skeptical to believe the dash, but now I know it's very close.

This might sound a little extreme, but I just bought a personal urinal so I can skip bathroom breaks on long trips ("The Little John"). It'll save me time and fuel.

My dash readout on my 2011 Jetta alway shows lower mpg than my calculated mpg. As much as 5 mpg low. I average 45 mpg in the winter and 55 in the summer even after my 245/40r17 tires with a 200 tread wear. I also use the AC very seldom. My best tank was 62.4 mpg with just over 900 mile and 15 gal of fuel.

94cobra2615 said:

This might sound a little extreme, but I just bought a personal urinal so I can skip bathroom breaks on long trips ("The Little John"). It'll save me time and fuel.

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yuck! On long trips, it's good to get out every couple hours to stretch the legs. Just like long plane trips, too much time spent sitting in the same position can lead to circulatory problems in the legs, especially if you're prone to blood clotting, etc. Of course you'll never know until the first time it happens.

jhinsc said:

yuck! On long trips, it's good to get out every couple hours to stretch the legs. Just like long plane trips, too much time spent sitting in the same position can lead to circulatory problems in the legs, especially if you're prone to blood clotting, etc. Of course you'll never know until the first time it happens.

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I guess I'll live on the edge and await my ambulance ride on the side of the interstate.

I may as well stop driving all together because I MIGHT have a wreck.

94cobra2615 said:

I guess I'll live on the edge and await my ambulance ride on the side of the interstate.

I may as well stop driving all together because I MIGHT have a wreck.

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You always go with DEPENDS and not bother with a personal urinal!