924 /944 fuel economy?

[alfadoc]

Originally Posted by djnolan

What would you expect for 3.0L V6?

I've considered this. My 911 gets a touch better mileage on average, but I drive it easier. My 3.0 Alfa Milano used to average 24, the 164s 22. As I said, might need an oxygen sensor.

[arominus]

I run 225/45 and 255/40 on 17's, they are super close to the size of the 16's. Keep in mind my high number is a pure Highway tank of gas running 65-75mph with all of the aero on the car.

[arominus]

Originally Posted by alfadoc

On my S2, in typical mixed city + 70 mph expressway driving, 19 mpg is the norm. A tank that's pretty much all highway 75-80 mph, 22 mpg. I think I've seen one tank that was 24.

I am running the stock 205/225 staggered fitment as far as tires go. I have a sneaking suspicion that if I replaced the O2 sensor my mileage would improve by 1-2 mpg. I need one of these:

You should do much better on your highway tanks, iirc my dad got 28 or so on a cross country run from colorado to chicago in the S2 with its original engine.

[Tony-K]

I drove a total of about 300K miles on several 944s since 1997. Many cross-country trips with multiple fill-ups, which gave me the opportunity to calculate tanks of entirely highway miles.

My 944s were all stock, all 2.5s 8-valves except for one S and one S2. With the cruise control on for most of those miles, I got anywhere from 28-31.5mpg, most often a couple of tenths under 30.

[Volhv]

86 NA,
Manual Steering,
AC Delete,
No back seat,
Light weight trunk carpet,
Rear wiper and hatch release motors removed,
15" Fuchs on stock tire size,
Turbo transmission,
No underfloor sound deadening,
Testpipe......

Got 8.4 L / 100km (28 mpg) on my last fillup.

[EPiK]

early 85, throttle cam, no cat, new injectors, new fpr and damper, new vacuum lines, new dme relay, new ref sensors, new headgasket, new o2 sensor, 88 tube header, new belts and water pump, PCG cam gear (+4*) and PCG crank pulley, stock (215/60/15 tires on Fuchs) new shocks, 82k miles

i have broken 18mpg once. stuck in the high 17s city/hwy average, fill up everytime full so i can do a full calculation on the mpg.

frustrating.

i am driving rather aggresively compared to some of you, but not in traffic. by habit I heel toe downshift, rev match..etc

i may try and drop that habit on the next tank, in the name of science

[racer]

Compare Original and New Fuel Economy Estimates

I don't actually notice my mpg. I know with the '87, 5th gear is quite low (or is it high) such that it does make a nice relaxed highway cruiser.

[v2rocket_aka944]

Originally Posted by EPiK

early 85, throttle cam, no cat, new injectors, new fpr and damper, new vacuum lines, new dme relay, new ref sensors, new headgasket, new o2 sensor, 88 tube header, new belts and water pump, PCG cam gear (+4*) and PCG crank pulley, stock (215/60/15 tires on Fuchs) new shocks, 82k miles

i have broken 18mpg once. stuck in the high 17s city/hwy average, fill up everytime full so i can do a full calculation on the mpg.

frustrating.

i am driving rather aggresively compared to some of you, but not in traffic. by habit I heel toe downshift, rev match..etc

i may try and drop that habit on the next tank, in the name of science

something may still be off?

i floor my car every time theres a decent gap until the next car, off most lights and onramps, constantly on the freeway from 65 to "redline in 3rd gear with a 951 gearbox" mph, stop and go traffic, light cruising, basically all the possible sports-car driving modes and still do 23-24 mpg consistently over a tank. and i have a MAF, huge injectors with a rough tune and 2* advanced cam gear (will try 4* soon).

[EPiK]

I have backed off of the downshifting and finally broke 170 miles on the half tank. I think it may have something to do with the richness coming off rev (idle dip when you let off the gas, you can smell the richness).
Thinking I might install the 88 maf and dme for my next tank full and see if there is any difference. I understand the over rich stumble coming off rev is corrected in the later cars.

don't know what else to do. everything else is new and running top notch. compression #s 175,180,180,182

i wanna drive my car like you do rocket

edit.. just had a thought. i'm going to check my FQS in the morning.. wondering if it possibly is set to step 2 (+4 fuel)

[v2rocket_aka944]

the only way 18mpg makes sense is if all you do is stop and go traffic.

[alfadoc]

Originally Posted by alfadoc

On my S2, in typical mixed city + 70 mph expressway driving, 19 mpg is the norm. A tank that's pretty much all highway 75-80 mph, 22 mpg. I think I've seen one tank that was 24.

It may be worth mentioning that I am running an Autothority chip. Might be an interesting exercise to swap in the spare stock DME I have and see how it impacts mileage.

[88Silver924S]

Here in Washington state I believe all gasoline is at least 10% ethanol with rare exception. Ethanol is less energy dense than gasoline so straight gasoline should get one better mileage. Does anyone know if the difference is significant? I usually get in the mid 20's of mixed driving upper 20's highway. My '88 924s has the higher compression "944" engine and uses the higher octane gas. Does anyone use "regular" gas in their 944/924s/951/etc? Do winter/summer blends change gas mileage?

[EPiK]

I made some changes, on the stock early 85 dme and maf I adjusted FQS to position 2, (-4% fuel) and saw a bit more mileage..finally in the 19s.

Then, I swapped to an 88 maf and dme and the car both ran smoother, the idle did not smell as rich, and I'm currently at the mileage that my low fuel light used to kick on at, with 1/4 tank to go.

Some discussion on another board has me thinking that the next tank full may be 87 octane, instead of the 89 I have been running. Will keep an eye here

[PorscheNut924]

Driving 3300 miles across the US with a big load of my stuff in the back of my 924S, I got around 25-26 MPG. On more normal highway trips without a lot of weight (and not going 80+ all the time), it has averaged around 29-30.

[MDH]

Last weekend went to Road America for the June Sprints.
Total mileage was 175 miles, 140 were highway at 75-ish.......with a couple of short runs to 90-ish.
The rest was country roads at 35 to 55 mph and moving to different locations while at track.
Got 29.1 mpg.
Stock 924s with 215/60×15 tires on 15x7 wheels

[Dr DIY]

Never checked the mileage of my Porsches and don't really care. I have a Chevy Spark for commuting - 45MPG. If I am worried about mileage, then any old Porsche would not be my choice. How do you expect good mileage with your foot to the floor?

[thomasryan]

15ish...maybe 20 if I drop it into 4th gear a few times but that could be the new small odometer gear.

[EPiK]

First tank with the 88 dme/maf and driving normal (redline shifts. .lol...). 19.6mpg that was on 89, just put 87 in and we'll see how that goes, smell is less rich so far and rev seems crisper so i can tell it leaned out.

I could care less about mileage also. Except that if others are getting a lot more, then there is an indicator that my car is not running at the top of its game. And that bugs me.
lol