is getting 300 miles or so on a full tank to empty good? just wondering since the cars is 20 yrs old or so.

 

Well, depending on what series you have you and if it is turbo or not, you should be getting anywhere from 272 to 450 miles out of a full tank if you pull up to the gas station on fumes. These cars get 17/25 from the factory, but after 20 years that goes down. Mine still gets the factory mileage, but I have a rebuilt motor.

Of course, these numbers will vary depending on the state of your motor and how much mixed driving you do.

I got those numbers this way...

S4 and all city = 17mpg x 16 gallon tank = 272
S5 and all highway = 25mpg x 18 gallon tank = 450

Numbers were rounded off for simplicity.

 

You almost never use the last 1.5- 2.5 gallons in a gas tank... so real range would be 250 miles and 350 miles for a S4 and 265 miles and 375 miles for a S5 provided you were driving as well as you could to meet the EPA test standards.

 

S4 TII
Best was on the way to LA

357 miles I put in 14.8 gallons afterward.

 

well its an 88s4 n/a. most all miles i drive are highway due to work. but figured it was pretty good seeing as my suv gets that as well. thanks for the feedback. only thing ive done so far is a k&n air filter, no others...........yet!

 

I hear ya, all these commercials for suv's (and some larger cars) tote "17/24" or "18/25" like thats supposed to be impressive. Meanwhile my FC is old enough to drink and she still gets that.

I'm pretty sure w/ an ecu and some tuning an FC could run close to 30mpg maybe a lil better. I'm not yet in a position to try.

 

Typicall numbers for most modern sports cars as well.
next too impossible to get 30 mpg on a FC, no matter what tuning you did.

You might be able to temporarily get that... running down hill with a good wind to your back, at a constant 50 mph.

But that is about the only time you will see 30 MPG in a rotary powered FC.

 

i gotta 88 n/a n i get like 100miles to half...lol 150 for 3/4 so idk if thats good...lol

 

On my trips to Omaha, Chicago and STL I was averaging 14/25. Not bad for a n/a with 119k on it.

 

With Intake and exhaust,MSD..so Pretty Well stock, I get about 25 Tops highway..I think that is Really good. I actually thought it would be Less...I do like to use the High rev's alot(for Pull to pass..and that Nice Sound!).But in town I baby it,so I don't get hassled.

 

Yes, but i was speaking in hypothetical terms which you would use the entire gas tank which I should have been more clear about. Sorry.

Anyways, EPA test standards also say "the majority of vehicles with these estimates will achieve between 14 and 20 mpg in the city and 20 and 28 on the highway" as per my dealership window badge. I'd post it up if I had a camera or scanner.

 

I envy you all...with that much miles/gallon ratio...

 

I get 21 mixed when I drive 'conservatively' in my S4 n/a.

 

S4 N/A - 200 miles to the tank... if im lucky...


...what?

 

I've gotten 400 miles per tank in my s5 n/a with half highway and city combined.

 

On mine i travel from my home to fresno, ca which is about 4 hours drive. about 250 miles. and i only use up 8.5 gallons. That would be about 28 miles per gallon if im correct. Only mod is K&N filter

 

i drove from ny to florida in my 87 N/A and i got around 26mpg all highway

 

Last time I checked I got about 15 in town and 22 on the highway, and Im still running my stock airbox from a car show trip. Boostedfc3s ran btwn 18-20 out to Illinois and back with his SAFC. I'd say those numbers are just as good as newer cars, without the hefty car payment lol

 

Around town I get 15-17 mpg in my 88 GTU. When I moved from northern Cal to Oklahoma 2 years ago, I got an average of 28.4 mpg for the 1700 mile trip.

 

I've really only done a full tank on highway driving once, and I got 28-29 mpg. This was on a fresh rebuild with ported intake and exhaust. It had a cone filter intake and a cat-replacement pipe to apex N1 exhaust. For some reason I never way that kind of mileage again once I put on my header, but it could have been other factors. I probably averaged about 80-85 the whole trip, sometimes as high as 95, with my windows down. If I had slowed down and had my windows up, I am pretty confident that I could have broken 30 MPG.

Also, as stated, DO NOT calculate MPG based on how mileage per tank. I have filled up when it was sitting on empty and it still had 2.5 gallons left, and I have filled up when it was in the exact same spot and had less than a half gallon left. The gas gauge on basically any car is very inaccurate in the lower part of the tank.
To get MPG, you take miles divided by gallons, there is no other way.

 

A better way to find out whether your gas milage is "good" or "bad" is to do this:

Fill your tank.
Reset your trip odometer.
Just drive the car as you normally would until you fill up.
Record miles on trip odometer, as well as gas you had to put in to fill up.
Miles divided by gallons=miles per gallon.

Not too hard, eh?

 

no ******* way. i don't believe it.

 

Keep in mind guys that driving style has a lot to do with mileage.

The best mileage that an FC will get is between 70 and 85 mph (I don't understand it either, but that is where they do their best).

I CONSISTANTLY got 30 mpg out of my '86 GXL using the stock fuel injection, 15 degree advanced timing, no power steering, no air pump, no A/C. I accelerated very gently, never exceeded 3500 rpm and used nuetral every chance I got, just the same it got 30 mpg.

I also got 11 mpg for 44 miles and 4 gallons at the dragstrip and 17 mpg for 110 miles and 6.5 gallons while autoXing. These were the only partial tanks I ever checked, simply because I was curious.

My best stock ECU mileage was 31.5 mpg driving 80 - 85 mpg down the interstate on a 95 F day.

Basically if you have good engine compression, accelerate gently and drive 70-85 mph, you should get high 20's to low 30's

 

Here's some of my mpg...
10.84969789
11.08811354
22.46897453
20.78227049
24.25531915
21.83933766
23.01381693
11.44400786
10.89867579
21.60533911
22.88592867
14.04095422
14.97948527
23.05433732
18.46236312
23.56626861
24.09230769
21.86765989
24.55517241
22.7091272
23.39853301
22.44504111
23.33252876
23.8468854
24.26514697
20.70511886

S4 NA... For now.... lol

 

It really is odd about the speed they get the best gas mileage. I'm sure some of it has to do with the good drag coefficient, plus the fact that I had nothing attached to the engine but the water pump and alt, plus a light flywheel.

That said, with my floorsweeper rebuild I just did in my garage (main problem is too high clearence on the side seals...) I still get decent mileage. When breaking it in, I got high teens. Once it was broken in, I was driving it like I stole it and got 14-15 mpg. Once it got hot outside a overheating problem developed and I got low 20's *****-footing it around to keep it from heating up. Once I get everything fixed, I'm curious about what the actual mileage will be.