fuel economy

[GPdriver1986]

I filled my GP up for the firsttime using my own moneyand because my odometer/trip odometer works. I pumped in about 45$ of gas at $0.799 per liter. From that I got 400km, I still could have gone maybe 10-50km but my gas gauge becomes inaccurate below 3/4.

 

45/0.799 = 56.3 L

56.3L /3.8 = 14.82 gal

 

400km*0.66 = 264 miles

 

264 miles/ 14.82 gal

=17.81 mpg

 

That is just city driving and I wasn't flooring it or using A/C, is that good for a 14 yr old 3.1 V6? The engine had a tune up done last year and I checked the spark plugs and still look like new, it also had fuel injector cleaner poured in last year, most of the other engine stuff was changed too.

[GutlessSupreme]

that's about what I get.. I have a heavy foot so mine flucuates between about 14 mpg and 21 mpg between city/highway

 

*according to my DIS..

[jeremy]

I get around 18-20 in the city and high 20s on the highway....mine is a '97 with the 3100....

[slick]

You guys are lucky. I don't even want to figure out the gas mileage I get.

[White93z34]

i've heard storys of 3.1s getting 35mpg on the highway, any truth to it?

[supreme_style21]

i've heard storys of 3.1s getting 35mpg on the highway, any truth to it?

 

My '89 did quite easily. My '94 sees 34 on a good day.

[phantomshado]

I nail down ~33 all the time on the highway, and I pull 23-25 in town.

[pitzel]

Yup, drove back from Calgary yesterday, a 700km run. Burned a little over 45L of fuel. That calculates out to 36.7 USMPG/44.14 Imp MPG. Went a shade over 90km/hr the entire distance.

 

My tricks: slow driving, mobil1 5W-30 in the crankcase, autothrottle enabled, windows up, air conditioner running half the time, brand new oxygen sensor, recently cleaned intake and throttle body, and 40psi in relatively new Firestone tyres.

 

With these results, I believe I could achieve a range of 1000km on a single fill of fuel.

 

(1992 Cutlass Supreme 3.1, 4-speed automatic, 4-door)

[rudefyet]

With these results, I believe I could achieve a range of 1000km on a single fill of fuel.

 

I've drove 500 miles (approx 833km) on one tank of gas and still had a more then a 1/4 tank left...so 1000km isn't out of the question

 

all highway miles..it calulated it out to 35mpg

[DiscoStudd]

My "thirsty" 3800 Regal gets around 22.5 MPG in city driving (that's with a heavy foot, and I also drive 10-15 MPH over the posted speed) and the best I ever got out of it in highway driving was around 28 MPG (after tuning it up and using the AC.)

 

I think the wife's 3100 Loomie gets around 23-24 MPG in city driving and the last time we took it on a road trip it got around 29 (again using the AC the whole time...)

 

I'd say if your spark plugs still look new (check the gap also) then change your Oxygen Sensor for good measure. Be sure to change your air filter regularly (like every 12,000 miles.) Also check the pressure in your tires...

[pitzel]

Another trick on the original poster's car. Drive it around the city for 10-20 minutes, letting it warm up. Now, park it, set the parking brake, and go smell the exhaust with your nose right up to the tailpipe.

 

If you can smell any sort of obnoxious odour, then you're probably running rich and you should think about replacing the oxygen sensor. At 110k miles, the sensor is easily due for replacement anyways.

 

400km's on that amount of fuel would involve some pretty heavy city driving. If you're in Canada, definitely run a decent quality 5W-30, dino or synthetic, really shouldn't matter in these engines. In dino, Texaco Havoline has always served me well, but i'm using Mobil1 synthetic now as I am extending my oil change intervals to at least 20,000-30,000km's (very safe on these engines if things are kept clean and filters get changed once in a while).

 

Other than that, good luck, and try a few things. Resisting the temptation to go fast, and proper maintenance are key.

[kfahn]

a more accurate way of measuring the mileage is to flll up all the way, reset the trip odometer, and when you refill take note of how many liters you fill up with. That way you don't count those few extra liters that are left in the tank still.

[z34_nut]

i don't really care, i'm paying 1.62 a gallon

[Bruticus]

i don't really care, i'm paying 1.62 a gallon

:x damn it still 2.10 in this crappy city :x

[THe_DeTAiL3R]

I get about 30-35MPG highway

 

max I'd say about 450km/tank mostly city driving.

 

The DIS on my 3100 gives me much better numbers, I can't wait to be driving that thing!

[DiscoStudd]

a more accurate way of measuring the mileage is to flll up all the way, reset the trip odometer, and when you refill take note of how many liters you fill up with. That way you don't count those few extra liters that are left in the tank still.

Exactly. I've been driving around the last week without the AC on, and when I filled up the Regal tonight, I calculated 24.9 MPG (city driving.) Not bad for a supposed "thirsty" boat-anchor motor!

[99RegalGS]

Holy cow Disco. My 3800 is great on gas, as long as I keep my foot off the floor. When I got the Cutlass in June I averaged 33MPG. (With AC on)

 

My Cutlass isn't too bad. I averaged 26 MPG on my 30 minute commute work this summer.

[DiscoStudd]

Holy cow Disco. My 3800 is great on gas, as long as I keep my foot off the floor. When I got the Cutlass in June I averaged 33MPG. (With AC on)

You got 33 in the Regal? Damn! I suppose I could get better mileage if I drove like a Grandpa, but people who drive the speed limit on the interstates around here get run over (not that I want to drive the speed limit anyways...) I guess the potential is there to wring out a bit more MPG, but I'm happy with what my car achieves. My old LeSabre (same motor) was lucky to pull in 21 MPG in city driving.

[99RegalGS]

Oh I wasn't doing the speed limit either. I think it was around 75-80 until NE then it was 85-90. I wish Interstates around here has a 75mph speed limit.