What can I do to increase fuel economy??

andrewb_1985

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Ive got a 2003 golf with auto trans and get (on a good tank) 40mpg doing 90% highway. From what i hear with auto trans and no current mods, these numbers seem to be common. But with the rising cost of deisel id like to know what mods I can do to improve mpg. I know there are different nozzels and chips available but which are for performance and which are for economy?. And what other mods of maintenance tips that can help. Thanks!
 

Joe_Meehan

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The one thing that makes the biggest difference is your driving style Drive like your grandmother and you will be doing it right.
 

puter

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swap to a manual. That will get you another 10 mpg.

Get chipped, that will get you another 15% or so increase in fuel economy.

Slow down on the highway, go 60 mph rather than 70, that will get you another 10%

Draft at 2 seconds back on semi's, that will get you another 10%

I currently get 55 mpg on my 2002 jetta without trying too hard. If I were to follow all the driving rules above all the time and not gun it (which I do at least once a trip for fun) I would expect to get at least 60 mpg.

My jetta is a manual with a kermaTDI (alligator) chip.

If you don't want to chip then advance your timing 3 degrees or so and you will see a 10% increase in fuel economy.
 

puter

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lol, Lnxguy, I thought you were talking about my post.

I was reading through it going "where the hell did I say something that wasn't true?"
 

n8ronJ

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So I average 48 - 50 mpg in my Jetta. I used to use PowerService additive and stopped just to see if there was an mpg drop. I couldn't document one anyways. I have, however, changed my driving style. And, not having much stop and go city driving helps me out too.
My next goal is to reach an average of 55mpg. You say that advancing my timing around 3 deg will add about 10%? Do I need vagcom to do this? If I can chip the car someday - do I need vagcom for that too?
 

puter

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You do need vag com. There is some concern about engine damage due to this, but there has not been any substantiation (read: a lot of people have done and and nobody has had any problems). do a search for "results are in" and you should find the thread about it. I did it myself (until I got chipped...trying to convince myself to do it again with the chip, that's a bit dangerous tho) and had no problems or damage, I have a friend that has his tdi longer than I had has it more advanced and he has had no problems. And there are literally dozens of people in the thread who have done it without any problems.

You will get more satisfaction out of a chip, but it costs more too :)

also, if you get a boost regulator ($35 - $50) you can adjust your boost up a bit and get an improvement. kermatdi.com has a few nice ones.

if you get the chip the boost regulator won't do you much good since the chip is already maxing your boost.

As far as chips go, I prefer the kermatdi chip because you can change it on the fly. If you get RC or any of the others you have to go to them to go back to stock or buy a second ecu. If you buy a second ecu the price is the exact same between kerma and any of the others. I have kerma and really like it.
 
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ruking

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andrewb_1985 said:
Ive got a 2003 golf with auto trans and get (on a good tank) 40mpg doing 90% highway. From what i hear with auto trans and no current mods, these numbers seem to be common. But with the rising cost of deisel id like to know what mods I can do to improve mpg. I know there are different nozzels and chips available but which are for performance and which are for economy?. And what other mods of maintenance tips that can help. Thanks!
Keep in mind you use app 375 gals per year!

(@ 40 mpg, 15,000 miles yearly high average, normal is between 12,000 to 15,000 miles) Under the same conditions with a manual @ 50 mpg)

I would use app 300 gals.

So really you are talking shaving a percentage % of 75 gals per year

( /12 mo= 6.25 gal per mo) or @ current price of 4.91=$368.00 year /12mo = $31. mo.

The premium at the time for a TDI over a 1.8T was (for me anyway) app 246. and at that such a Bru HA HA!!? So really, the 10 mpg difference is the operational premium for an automatic. You certainly can do the low hanging fruit stuff, but are you really ok with radically altering your behaviors? So in closing, if I follow even more extremely, item/s 2,4, I would swag a boost from normal 48-52 mpg to 52-59 mpg (5 mpg or 10%) . In effect, it would be a different game for max 27 gals/12 mo=2.25 gals mo @ 4.91=133. year/12 mo= $11.00 per month.

Here are some of the easy stuff:

1. tires @ 85% of max sidewall, effect: increases chances of longer tread life, better mpg.

( If you have deviated without research from the oem tires, you have figuratively shot yourself in the foot here)
(for example, I am @ 108,000 miles and the oem GY LS-H's look good to go to 130,000 miles, PSI has been 38-36 fronts, 38-34 psi rears. I am by no means using many fuel miser procedures)

2. find the best rpm for best mpg (manual between 1750-2200 rpms)

3. the normal 360 degree situational awareness; reflected in things like: not accelerating to a stop light, not tail gating, etc.

4. driving your automatic with hyper awareness; SO given whatever situation, you are ALWAYS at the low side of the fuel consumptive curve. (WAY too obsessive compulsive for my personality)
 
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oilhammer

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outside St Louis, MO
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There are just too many to list....
I'd say 40 is still pretty good, tires make a difference too. Lots of people put the wrong tires on these cars for some reason, or cheap ones, so be sure you have the proper ones and they are aired up.
 

jettawreck

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Read and search in the "Fuel Economy" section till your eyes bleed or fall out. There is so much info, opinions and suggestions there it'll make your head swim.
It depends a lot on what your objective is...
Do you want a few more mpgs and save some money or are you on a mission to get every last mile out of a gallon no matter what it costs? It's all been hashed out many times but it is always a fun read.
Slow down, anticipate traffic ahead, coast as much as possible, advance your timing, air up your tires or consider some low rolling resistance ones, slow down, buy a Scan Gauge, did I mention slow down....
Chips may up your mileage, but will they pay for themselves?? I don't know. I put in a set of Sprint nozzles to bump up the power (which they did quite nicely, thank you Kerma) and got a bit of a mpg increase, too. Will I save any $$$? I doubt it, but it sure made a better feeling vehicle out of it, so the mileage increase was a bonus.
Start saving up some money now to replace that automatic when it goes with a manual, that will certainly up your mpgs.
 

andrewb_1985

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2003 Golf ALH TDI 5-spd
jettawreck said:
Chips may up your mileage, but will they pay for themselves??
Well I decided to do my own calculations to try and justify purchasing the Kermatdi w/ Q Loader for $625. Let me know what you think of my numbers...

I drive 50 000Km /Yr
Thats 959Km /week, which is exactly how much I get per tank @ approx. $80 per fill.
That runs me about $4170/yr.

Assuming I can get 15% increase in fuel economy I will get about 1102Km /tank decreasing my annual fuel bill to $3629. A savings of approx. $541/Yr.

Considering I have 2 yrs left on the loan it seems like it might be worth it.
 

puter

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Add in the enjoyability factor.

You will simply enjoy driving your car more when it is chipped. I do, I have no regrets about chipping it. Chipping also gives you a step into a lot of potential future upgrades. If you upgrade your clutch, you can bump the chip up (for free). Blown turbo? get a better turbo...and upgrade your chip to take advantage. bad injector? Get sprint 520's. etc. etc.

Just a note, your clutch may not be able to handle the chipping. You need to accept that you may have to change out your clutch as a result of getting chipped, it will run you $800-$1000 including labor, if you do the work yourself the parts are about $350. The way I validated it for myself is the fact that the clutch is a wear item anyway, so I'm just changing it ahead of time. You can just swap in a VR6 clutch if yours goes out and it will handle pretty much any increase in chipping you will do.
 

andrewb_1985

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2003 Golf ALH TDI 5-spd
Sorry Puter, I have an auto so no clutch here. I will get a manual trans for my next car for sure, however I dont think that will happen for another 2 years or so. But with my auto, would I be getting into any transmission problems with the chip?. I was told that increasing the power output by more than 15% with the auto will blow the trany. So with this car im more concerned with economy and not so much with power increase.
 

LNXGUY

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Get yourself some nozzles and be done with it... You'll see a decent %5 gain in fuel economy with upgraded nozzles.

Not to mention about 15hp and 40ftlbs
 

puter

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andrewb_1985 said:
Sorry Puter, I have an auto so no clutch here. I will get a manual trans for my next car for sure, however I dont think that will happen for another 2 years or so. But with my auto, would I be getting into any transmission problems with the chip?. I was told that increasing the power output by more than 15% with the auto will blow the trany. So with this car im more concerned with economy and not so much with power increase.
You are going to see transmission problems anyway. Expect the transmission to last about 120k miles before it dies. The good thing about that is that it is an excellent time to do a manual swap; doing a manual swap and replacing with an auto cost almost exactly the same.

I am not sure if the chip will affect the life of the auto, it could a bit. The good thing about the kerma tune is you can let them know you have an auto and they will adjust the tune to help preserve your trans.
 

jettawreck

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andrewb_1985 said:
Well I decided to do my own calculations to try and justify purchasing the Kermatdi w/ Q Loader for $625.

Assuming I can get 15% increase in fuel economy I will get about 1102Km /tank decreasing my annual fuel bill to $3629. A savings of approx. $541/Yr.
I truly think that a 15% increase is very optimistic. If it really was probable I'd most likely be first in line for chipping. Any hard data anyone has I'm willing to look at seriously. Most seem to be about like my nozzle swap-preformance gain for sure and a bit of mileage gain if/when you keep your foot out of it. ;)
 

RichBoss302

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Bigger Rims hurting MPG?

I just bought a 2000 Jetta TDI with an Automatic and 15" aluminum factory wheels. I want to put the 16" BBS rims, I think they came on Wolfsburg Edition Jetta's, and want to know if just the 1 inch increase in wheel diameter is enough to REALLY hurt my MPG?
 

puter

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I believe that increasing wheel diameter will help if you don't add too much weight. You will travel further per revolution
 

LNXGUY

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The wheel diameters are the same, regardless if they are 15" or 16" wheels. The only thing that changes is the sidewall height of the tire...


I hope people don't increase their sidewall height hoping for a increase in mileage, lol
 

RichBoss302

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LNXGUY said:
The wheel diameters are the same, regardless if they are 15" or 16" wheels. The only thing that changes is the sidewall height of the tire...


I hope people don't increase their sidewall height hoping for a increase in mileage, lol
I thought I heard that wider rims make for more friction thus causing more effort to turn the wheels in order to move the vehivle down the road. Wider rims = more contact patch = more friction?? How could a taller tire make better mpg.....if BIG tires on a 4x4 made for better economy then wouldn't the 4x4's get GREAT mpg? I am confused on this one!
 

puter

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it is a balance thing. The large truck wheels are heavy and have lots of friction. If you were to increase the total diameter (wheel and tires) without adding weight and not adding too much friction you will improve fuel economy.
 

jettawreck

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puter said:
I went from 48 to 54 mpg.
That's impressive. Do you have some idea if your driving routine is similar and can you attribute most/all of the increase to the chipping or did you do other mods?? Interesting to consider...
 

puter

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I've adjusted my driving habbits a bit as well, but a large amount of the change is due to the chip.

I got similar results when I advanced my timing (I have not done it since I got chipped since that already advances the timing and I'm not confident that the timing values I see are the actual timing values).

I would say I went high 48/low 49 to 52 due to chip alone and got another 2-4 due to driving habbits. I have a feeling my next tank is going to be around 56...but that is all driving habits and perhaps the egr delete I did.
 

n8ronJ

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Advantages and disadvantages of egr delete? I've read it here a little but am not sure if it's something to consider.

On advancing timing - is this simple to do with vag-com? I don't have vag-com but found a local source thru the club here. If I use this guy - do I tip him? offer him money for the help? what's the protocol here?

Driving habits are certainly the #1 mileage gainer or loser. I've had my TDI for 10 months and gained 3-4 avg mpgs thru becoming a more concious TDI driver. Heck, I've started driving my wife's Jeep GC better.
 

LNXGUY

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puter said:
it is a balance thing. The large truck wheels are heavy and have lots of friction. If you were to increase the total diameter (wheel and tires) without adding weight and not adding too much friction you will improve fuel economy.
You've be better off overflating your tires..

Increasing the overall wheel diameter to increase mileage is useless.
 

puter

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Why? If you increase wheel diameter and don't increase weight you should go further per Revolution, which means going further for the same amount of work from the engine.

I'm not saying that you're wrong, I'm just trying to understand why you're right :)
 

Schwabe

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Seriously, recommending to increase power to increase fuel economy. I mean seriously.

here are some really proven tips, and currently I am pushing 70MPG (and that is in a 50/50 city/HWY mix):

http://ecomodder.com/forum/EM-hypermiling-driving-tips-ecodriving.php

What will give you the greatest fuel economy boost is the right-foot-mod.

Drive 5 miles under the speed limit (every 5 miles cost you 10% fuel efficiency)

Coast when ever possible.

Accelerate slowly.

Stay under 2,000RPM

Try to avoid the turbo to kick in - kick it at the end of the day to clean out the carbon.

Turn your engine off if the traffic light just turned red. Less fuel to start your car after 7 seconds then letting it idle.

Don't use your brakes - Look ahead in traffic and leave a nice buffer, when the brake light s ahead of you come on - coast in gear, that cut of the fuel supply.

You can easily gain 20-40% fuel economy over normal driving.

Before I followed any driving techniques I averaged 550 miles per tank on the above 50/50 mix with a 51 mile one-way commute, now easily over 750 per tank. No mod will give you similar results. Other then buying an efficient car from the get-go.
 

LNXGUY

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puter said:
Why? If you increase wheel diameter and don't increase weight you should go further per Revolution, which means going further for the same amount of work from the engine.

I'm not saying that you're wrong, I'm just trying to understand why you're right :)
The problem with your theory is that doesn't happen. The engine is going to have to work harder to rotate the larger diameter tire. You are also going to be higher off the ground, so I am sure wind resistence will also come into play...

If it actually did have a decent affect on mileage, don't you think all of us would be doing it already? :)

I average about 1100-1200km's per tank in the summer, by simply setting the cruise at 70mph :)
 
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