Help me increase my MPG's

[redline380]

So I do a lot of driving, around 180 miles per day when I commute. A few MPG's could make a big difference. I am talking about my Avant here, which is a bone stock 2000 1.8tqms.

My base line is around 26mpg's. I will not consider changing my driving style, which is about 80mph when I can and having to stop for about 5 lights each way. I do hit traffic sometimes, but my mpg's are usually consistent around 26, with a low of 24 and a high of 28.

The car had a couple DTC's, one of which was secondary air (I removed the system), the other was p1113, something about fuel/air metering. There was a b1s1 heater code for a while too. Anyways, somebody gave me a handful of 02 sensor he had sitting around. They were off an S4, but brand new OEM units. I wired one up this weekend and deleted the codes. On my commute this morning, I my gas gauge was a little better than normal, but only time will tell. 75 miles alter and no cel (it will pop up soon due to no secondary air).

So, I am wondering what you guys think. Should I grab some new injectors? Maybe have mine rebuilt?

Other things I am considering:

New spark plugs to something like the PF line of NGK.
FSI coils
Change fuel filter

What else should I try? 30mpg's is my goal, but the car does have 223k on it.

[Davdraco1]

Best I ever averaged on a highway trip was almost 29 mpg and that was with speeds over 100 once in a while. Car had 140k on it at that point with a full exhaust and no cat. Stock everything else on 93 octane fuel. Average speed was prolly around 80-85. If you doing those light that's prolly what's killing you. I have seen people changing fuel filters and just gunk comes out of the old one. So a new one might help some. Who knows.

[LA4]

I ran a set of the expensive platinum NGK spark plugs. Not only was there no improvement in MPG, but I had more issues with the car misfiring than ever before. Checked the gap multiple times and it was always correct. Save your money and stick to the BKR7s in my opinion. Biggest waste of $50 I ever spent.

Also... 180x5=900. Damn... That's almost 1k miles a week on a B5 with over 200k. Very interested to see how the old girl holds up.

[chris164935]

How many miles do you get per tank? For a while, I thought I was getting shitty mileage per tank (about 350), but ended up finding out that my gas gauge was way off (it's $100+ to get a new level sensor, F that). I just go by mileage on the odometer now. I drove the car until I hit about 420 miles and then filled it up (probably could have gotten a little more, but didn't want to risk getting stranded). It was about 16 gallons of gas. I do mixed city/highway driving (but more city than highway), so 26 mpg is about right. I have a test pipe, ALL emissions stuff deleted, FSI coils, and some $30 Brisk spark plugs (not worth it, by the way). You could try replacing/cleaning all of your sensors. Clean your throttle body and perform an adaptation. Maybe run some Seafoam in your gas tank (or do a quick cleaning via sucking it up through a vac port). You could try an aftermarket air filter (one that allows more air flow and is washable). Install a splash guard or whatever on the underside of the car to help with aerodynamics... Something more drastic, but if most of your driving is highway speeds, maybe a smaller 5th gear...? Another drastic measure, don't use A/C and/or remove power steering. Also, wash your car more often? Lol.

[Wrath And Tears]

He would want BKR6E's for the stock Avant. 7's would foul quicker. How is the body of the car? no major dings, no parts or trim missing? Do you drive with the windows or sun roof open? What about A/C? Reducing electrical loads as much as possible can potentially help gas mileage. How is the gap on your front bumper? Do you have a front license plate (recently took mine off and it seems like my mpg went down )?

Also silly, but how often do you wash and wax the car? A good polish on the old WWII fighters would give them an extra 5mph, no clue how that affects cars.

As far as what to try, if you can get some BG 44k and ...MOA i think (fuel and oil additives), its more or less like sea foam but I use a can every once in a blue moon. Hasn't done any harm, doesn't mean its done good though.

I usually average about 28mpg mixed driving and up to 35mpg with all highway driving. Figure at 80mph speeds I would get around 32mpg. I have a sedan and FWD. I know my sticker highway number is 30, the quattro is 28 I think. No idea if there is a difference between sedan / avant.

[jaydee23]

i drive 8 mins to work everyday. All side roads. I get 16-17 mpg.

[crazexr7]

- Drop some weight
- Def change the fuel filter
- Clean injectors
- Lower your car (I've read it can help at highway speed driving)
- Change your style of driving. I know you're not willing but it will save you a bunch of mpg's if you're easy on the gas pedal and not accelerating like a bat out of hell.

[grifrowl]

Transmission or just 5th gear from a 2.8. Or go hog wild with a 6 speed swap.

[redline380]

I drove the car until I hit about 420 miles and then filled it up (probably could have gotten a little more, but didn't want to risk getting stranded)....Install a splash guard or whatever on the underside of the car to help with aerodynamics... Another drastic measure, don't use A/C and/or remove power steering. Also, wash your car more often? Lol.

-There limited reason for me to stretch my tank. After two trips, I am at roughly 360 miles on the tank. So I stop and fill up at that point because I wouldnt be able to make it one way without filling up
-I will be installing my aluminum skid plate come winter
-I think I might remove the AC belt over winter. But I never use AC in the summer either, I'm a windows down kind of guy. You'd think that would reduce my mileage but I haven't noticed a lick of difference.

- Drop some weight
- Def change the fuel filter
- Clean injectors
- Lower your car (I've read it can help at highway speed driving)
- Change your style of driving. I know you're not willing but it will save you a bunch of mpg's if you're easy on the gas pedal and not accelerating like a bat out of hell.

Maybe Ill get to the filter this weekend. I have a spare at home
Would like to clean injectors but I cannot be without the car so I'd have to borrow a set for the mean time
The car is already lowered, the only mod on billstein struts and HR springs
Not going to change my dirivng, but it will naturally slow down when the snow flies

Transmission or just 5th gear from a 2.8. Or go hog wild with a 6 speed swap.

I paid $1000 for the car, not going to 6 speed swap it. I wouldnt even do that to my hopped up sedan. And even with 223k on it, the stock tranny is doing quite well so I'd hate to open it up when nothing is broken.


I should be able to update this tonight with the first tank with a new primary 02 sensor, still no CEL. I did not reset the ecu, so long term fuel trims are still there.

[pbcrazy]

-I think I might remove the AC belt over winter. But I never use AC in the summer either, I'm a windows down kind of guy. You'd think that would reduce my mileage but I haven't noticed a lick of difference.

Anything over about 45mph it is more efficient to use AC rather than keeping your windows down, however, if you are going to have the windows down anyway, deleting the AC system would not only reduce weight and delete one belt, but it would also let me more air through the radiator (no condensor). You could also get an electric fan and have it turned off when you are going 60+ (and pretty much all winter) since the mechanical fan isn't doing anything anyway.

[grifrowl]

I paid $1000 for the car, not going to 6 speed swap it. I wouldnt even do that to my hopped up sedan. And even with 223k on it, the stock tranny is doing quite well so I'd hate to open it up when nothing is broken.

Understandable. However you aren't really going to notice much measurable mileage increase without some sort of drastic change. A junkyard 2.8 transmission swap is probably cheaper than a set of low rolling resistance tires just to put things in perspective.

Try advancing your ignition timing conservatively. Substituting to an electric fan with a shorter accessory belt might help as well (Possibly shorter duration of warmup enrichment sequence, slightly less parasitic loss on the highway if you use a shorter belt).

[redline380]

Anything over about 45mph it is more efficient to use AC rather than keeping your windows down, however, if you are going to have the windows down anyway, deleting the AC system would not only reduce weight and delete one belt, but it would also let me more air through the radiator (no condensor). You could also get an electric fan and have it turned off when you are going 60+ (and pretty much all winter) since the mechanical fan isn't doing anything anyway.

I wont take the AC out. I use it occasionally in this care when traveling at freeway speeds, but if I come to a stop light or go through town, it gets turned off and the windows go down.

Keep in mind here I am not going to be spending $1000 or something to see 3 more mpg's. It would take A TON of miles to see a return on that. Some stuff could be considered okay since it is a high mileage car anyways and some stuff needs to be periodically replaced.

[19birel]

From what I've experienced, besides keeping up with maintenance, driving style is the best way to increase fuel economy. That being said, you don't necessarily need to drive slower, I have found that there are a few mpgs in not accelerating hard after lights and just easing your way up to your desired speed. You're not going to get to your destination any later by taking a few extra seconds to get to 80 but you'll save some fuel by doing so.

[redline380]

Results are in. New o2 didn't do squat, still at 26mpg. I feel like I should be able to pull 29-30, even with the way I drive

[Davdraco1]

Your asking for more mpg then what was expected from the factory which was 28 highway? Correct me if I'm wrong. And usually those numbers are when the car is off rolling down hill with a tail wind. On another note, I've heard that some people have had very conservative tunes focused on mpg.

[pbcrazy]

Results are in. New o2 didn't do squat, still at 26mpg. I feel like I should be able to pull 29-30, even with the way I drive

On a completely stock car, I would agree. I got 33 driving 75-80 for 5 hours straight (couple stops obviously). I would try the fuel filter next, if doesn't help at all then it has to be your driving style, and without changing that at all you're not gunna get very far

[redline380]

I would try the fuel filter next, if doesn't help at all then it has to be your driving style, and without changing that at all you're not gunna get very far

Driving style and MPG's are important, but keep ing mind the figure that actually determines fuel use is not MPG's but rather gallons per hour. And that is a little more difficult to calculate, but still doable.

[Kamil P]

You will not get better mpg without spending coin. 26 is pretty good it's a quattro car.

[aysix]

Yea 26 is good for an awd car. If you want better MPG get rid of it and get a fwd b5 passat for a little more mpg.

[SN95Audi87]

Amsoil High efficiency air filter (cleanable)
OEM Audi Fuel Filter
New Spark plugs
Amsoil Performance Improver gasonline additive

Other than those items, I would check all the little things on the car that could effect mpg. I would do engine flush, inspect brake system for drag, etc... I recently went to VA and average 31 mpg on mine with a exhaust leak and stock suspension. These cars like either be at 55mph for cruising or 75MPH at 3k mark....when driving.

[wolfe2118]

Lower the car to decrease drag, use clear tape on all of the body gaps, belly pan as already suggested, thinner(and higher pressure) tires...and everything that everyone else has suggested. Have you ever considered just getting a different car? As much as I hate to say it, you could spend less than a grand on another car and get at least 10MPG better on the highway with less maintenance running 87 octane. The money you saved in a year would pay for the car.

[crazexr7]

Swap in a quattro 1.9l TDI

[redline380]

Have you ever considered just getting a different car?

This is an Audi forum. I haven't driven anything besides an Audi in the last 7 years.

I don't care about the best mileage I can obtain; I care about the best mileage I can obtain with the car I have, the car I want to drive.

Swap in a quattro 1.9l TDI

Funny you say that. Had my fiance pick up a 00 jetta tdi for $600 bucks a while ago. I sold it last night for $1200. Would have been a great swap opportunity. But no, I do not have the time to do something like that.

[A4ski]

I'm surprised no one has said tires. Everything you tell your car to do goes through the tires. I know this is an Audi forum, but in my DD, which is not an Audi, but gets a minimum of 400 miles a week of work, I keep track of my MPG religiously (reset trip OD every fill-up and divide current reading by number of gallons the tank takes at fill-up. I have done this at every fill-up for 6 YEARS). When I first got it, I averaged a solid 31 MPG. I got two new tires on JUST the drive wheels, and it shot up to a solid 36-38mpg, and on a 1000 mile trip, I got 46mpg, when prior to the tires, pure freeway driving got me 39. Good tires and good alignment are the most fundamental things that affect your MPG, try riding a bicycle with low air in the tires and you'll see what I mean. After some careful math, I realized that my $400 set of tires paid for themselves easily in 6-8 months, but that was when gas was $3.50 a gallon. And if I am lax on checking the tire pressure, I know because my MPG goes down by 3-5. I get about 29 in my A4, but it's FWD and I really don't keep track of it the way I do with the Saturn. It has 4 new tires, but they were the cheapies. Just a thought. Good luck!

[redline380]

I'm surprised no one has said tires. Everything you tell your car to do goes through the tires.

Tires are good. Some sort of goodyear a/s. I will switch to my winter tires when the snow flies. However, the tires on there are old. My car sat for two years before I resurrected it. Plenty of tread left though.

[3 bar]

A chip actually improved my mileage. Also I'm swapping in a 2.8 trams this month so I'll keep you posted. I'm getting 28 mpg out of my 1.8T with a FTG K04-15XL GIAC P16 chip, Techtonics high flow cat, custom 3 inch exhaust and running on 18s with my current setup. I tend to drive around 70-75mph back and forth to DC and NC. You might also want to see if your cat needs to be changed.