ChaseN

I got 29.5mpg on a roadtrip from Harrisonburg, VA to Atlanta...I have 18s, with an overall diameter appreciably larger than stock, so I can't imagine the speedo/odo reading too fast/far anymore...I'm lowered, but 3.8 splitters and an RS America wing I would imagine increase drag over the stock C2 shape. I also have a secondary bypass and Steve Wong chip, maybe that helps?

35mpg though, I think would be impossible. Not gonna happen.

porschapete91

G'day Crew,just reading the spec's on a 997 GT2 and according to the blurb it has a Drag coefficient :Cd 0.32 which I think is the same as the 964.

N51

Paul,
With my PBox, speedo accuracy is good up to ~80mph. Only 2% optimistic at 100mph. Haven't checked the odo, but driving at extended 90mph+ across the high desert, the car averaged 27mpg. Certainly, Motronics was leaning things out a bit.

walterj

I get 27 at 80mph with a stock airbox, lowered to RS spec and I thought that was excellent. To get 35 I suspect I'd be so lean I'd be in danger of holing a piston.

Manny Alban

I got 30mpg on the way down to Charlotte for the Parade from Baltimore. I was doing between 65-70mph following two friends towing with open trailers. It was pretty wild pulling into gas stations when their tanks were 1/4 and mine was still 3/4 full. On the way home, I was solo and did between 75-80 and got 25mpg. AC was used on both trips. Compared to my foul weather daily driver, my 02 Suburban, the C2's gas mileage is like a hybrid

elbeee964

"We were hybrid(-like) even before Al Gore invented the internet. The Porsche 964."

aeroman

I have GPS and my speedo tracks right with it. maybe 1 mph apart. maybe a bit more in the 150 range (2-3 Mph).

Where did you get the speedo is 5% off?

911wings

My speedo is dead on to 100 mph. At least that's what the officer told me. Not a fun ticket to get but then again I don't get caughtthat often.


I think my mileage is a combination of my easy highway driving, having the car lowered (which ought to decrease my cd), having the K&N and no cat & g Pipe.

I've had the car weighed and it's 2967 with half a tank of gas. The American C2 tanks are 20.6 gallons I believe or maybe that's my truck's tank and it's 21.6

Christer

yeah...on my Motec enhanced car I think I averaged around 24mpg down to Le Mans in 2006....and lets put it this way....70mph was not really on the cards....we were doing between 80 and 100mph allegedly and traffic on the way as well.

On the way down from 9M last time, I filled up when leaving and I did 80mph pretty much allt he way down the M1 apart from some minor traffic hiccups and after I filled up again at the M1/M25 services some 150 miles from Warrington I would guess - I calculated the fuel consumption to be just under 30mpg from memory. Obviously, this was when the car's engine was new the second time round so it was easier to refrain from WOT all the time...

35mpg.....why not..in a standard car...unless the Motec is more efficient....? In any case, it certainly is NOT typical consumption for a 964.....

Christer

I have never know the error of a speedometer to be in percentage terms. All the cars I have owned I have verified with my Sat Nav and the Snooper 'speed safety and camera avoidance system' and my 964 reads around 5.5mph faster than actual speeds....at ALL speeds. Your comment suggests that if the error is 5% that at 30 mph if the error is 5.5, then at 150mph the speedo would show around 177.5mph which is not true.

The same for the BMW, and also the Vectra I used to own - the BMW reads about 4mph fast, the Vectra just under 5mph....and none of the errors increased with speed....so in any case, on 4 different cars I have tested then any "error" is certainly * NOT in percentage terms.......

springer3

My comment was based only on a spot check at highway speed to see if Porsche was taking advantage of the 5% allowable odometer error permitted by the US Gov't. Unfortunately they are. Mercedes to their credit is always spot-on when I check them. Speedometer error can't be expressed as a fixed offset either. The needle would point at a brisk walking speed when the car is stopped.

The subject of the thread is the 35 MPG claim for a 3.6 liter 964. That is about 40% higher than the best that most of us get. I don't find that credible unless he ran 100 psi in the tires, ran down hill, had a strong tail wind, and had some odometer error. It is also possible that at the fill-up, he put in less fuel, perhaps because the pump had a different shut-off, or perhaps the ground was tilted differently from one pump to the next. 35 MPG is possible, but not if you drive the way Porsches are designed to be driven. We all feel the pinch at the pumps these days, but get a Civic if you need 35 MPG.

Blown Away

My Euro spec 91 C2 5 speed manual with Cat Driver's Manual has a fuel economy figures insert.

Believe it or not:
Simulated Urban Driving - 16.5mpg (Imperial)
Constant 56MPH - 36.2mpg (Imperial)
Constant 75mpg - 29.1mpg (Imperial)

C4 5 speed manual with Cat
Simulated Urban Driving - 15.8mpg (Imperial)
Constant 56MPH - 35.3mpg (Imperial)
Constant 75mpg - 29.7mpg (Imperial)

I still can't see anyone achieving these figures - If they do, they should have their keys taken away from them for abusing their car.

I might just get close to those figures on my PS3 or X-Box