Menu toggle

Miles Per Gallon

I rarely put in 98RON into my 944 (Is there much benefit to running it on 98? I know manual says 95 is fine...). Last time I filled up the tank to the brim I hit around 350 miles to the tank.
 
Coming back to the fold after years away (last cars were a 250 and a 968), I was pleasantly surprised to get over 35mpg across Europe in a late series one car. This 2.7l gave me a nasty surprise on my first journey back from Edinburgh on the A1 though - not much over 20mpg! I believe that it was due to my being used to a much lightened and very nimble car, but I cant be sure.
 
300 miles from a full tank on my 2.7 and I don't have a particularly heavy right foot. Does this sound right?
Click to expand...

If you mean a full tank, check your fuel lines aren't leaking. Calculate the actual MPG though, as the guage is so hoplessly inaccurate that you might have only used three-quarters of a tank.

A lux should hover around the 30 MPG mark in general, careful driving. It plummets when pushing hard, high motorway speeds or heavy traffic, of course. I used to get to around 360 miles in VJ before I worried about filling up, and often 400 and never ran out. I don't know whether the tanks are the same size in a 2.7?
 
Series one cars and 924Ss have a smaller metal tank: all series two cars have the same sized plastic tank.
 
My S2 driven conservatively on moderate journeys can provide an average of 28-29mpg across a tank - that's getting to 400 miles between fill-ups on a regular basis. In town, I can see 18mpg across a tank (which is what it worked out at last time I filled it.)

Record best was over 33, which is about 430 on a tank. Ironically while giving it serious hoof across Scotland, on 95ron fuel. The loss in economy is in braking and accelerating, and sustained high speeds avoid this ... (something the idiots who run road policy should realise when they put in 'traffic calming measures' and multiple speed bumps. They increase fuel consumption and increase CO2 output - if anyone is stupid enough to think that this is bad for the environment. Oh, it also bring in more fuel revenue. Perhaps that's why they do it ... )

Higher octane fuel returns a better MPG that more than pays for the more expensive fuel. It's worth the investment in my book. Also summer motoring improves MPG by around 10% as the air is thinner (warmer) and pushing a car through it is easier.

(Should anyone wonder then yes, I have monitored every drop of fuel that I have ever put into my S2. Sad? Very .... [:mad:] * )


Oli.

* - I shall await someone telling me that I have used the wrong smiley!
 
Interestingly I find my 'S' gives better mpg on tesco's 95 Ron that it does on their 99Ron,. Either way I have never cracked 30 mpg, and this is on a steady 33 mile each way commute to work on a quiet duel carriage way averaging 65-70mph.
For info my porsche handbook states 34.7 mpg at a steady 75 mph ! and an incredible 42.9 mpg at 56 mph . I think Porsche may have been optimistic with their readings ! [:D]
 
ORIGINAL: ChasR

I rarely put in 98RON into my 944 (Is there much benefit to running it on 98? I know manual says 95 is fine...). Last time I filled up the tank to the brim I hit around 350 miles to the tank.
Click to expand...

I'm wondering this ... in my manual for my 1984 LUX it states (from memory as I don't have it to hand here) "only use 98 RON petrol"

What are peoples thoughts on this?
Is there any issue or worry about using standard 95 RON? Is there any real benefit in performance and economy when using above 95 RON?

(incidentally I've got quite a way over 300 miles on my 2.5L tank)

Cheers!
 
I used to get 24-25mpg in a mixture of town driving and driving to work (some stop start) at 40-50mph.

Long journey, regularly 30-32mpg. Best I ever got was due to wheel wobble (tracking out), I kept my S2 to 70mph and got an unbelieveable 36mpg!!!

But then again I am not a particularly fast/ aggressive driver.
 
Early cars should run on 98 - sticker inside of filler flap says so too - mine is certainly smoother with sharper pick up with it.
Mever checked mpg - didnt buy it to care about that!
Mike
 
Thnks chaps for all your replies.

I've calculated my MPG to be 23.5 - not great [:eek:]. I think it may be running quite rich as there is a slight smell of fuel from the exhaust fumes. Can this make a big difference to the MPG? Is fuel mixture an easy adjustment on these?
 
I get around 25-26 mpg from my 944S2 in normal mixed urban I suppose they would call it and well over 30 on a long run. When I had a 924S I got around 26-18mpg mixed and around 35 on a long run. I generally use 95 octane as I have not noticed any improvements for the extra cost of 99 octane even after a number of tanks full and I must agree that the fuel gauge is notoriously unreliable although having said that mine goes onto reserve and the light comes on with around 2 gallons left which is what it says in the handbook.
 
I've calculated my MPG to be 23.5 - not great .
Click to expand...

That's low, but it's so hard to judge as we've no real clue as to the sort of journies you do, or how you drive. It's winter, which makes a slight difference, and as mentioned a good service will improve things. As will tyre pressures.

All I can say is that my Lux very rarely went less than 30MPG on a tankful, if ever. That included a good mix of urban short runs, A-road blasts and motorway driving at a healthy cruising speed, probably as near to an average useage as you would get. I'm not heavy-footed, but it was always driven "enthusiastically", and often on runs would be in convoy with the Turbo boys, so I was always playing catch-up to an extent.

The one really bad mileage I got was almost no miles to a full tank. That was the fuel line giving up, though. Worth checking.
 
I have just had my car serviced at OPC, they inform me that the MAF is not functioning correctly it is running at 3.5% CO and it should be 1% and this is causing the excessive fuel consumption, now I don't know much about this sort of thing, but could this also be your problem?

Prehaps some of the more knowledge guys could comment?

Regards

Andy
 
ORIGINAL: zcacogp

My S2 driven conservatively on moderate journeys can provide an average of 28-29mpg across a tank - that's getting to 400 miles between fill-ups on a regular basis.
Click to expand...

That's because you drive like a girl[8D]. Get a turbo that'll soon stop you measuring! I can watch the fuel gauge move on full boost[:D].. mind you it still does over 30mpg on a long cruise (when I'm waiting for my friend in his S2)
 
From the responses here I'm beginning to get the feeling that there is something seriously wrong with my fuelling [:(] if I am only getting 26-28mpg at very best.
I dont really understand why that should be as the car is driven daily, serviced regularly by a respected Indy, and recently had the injectors cleaned.
The mpg as such doesn't bother me, more the fact that something is clearly amiss.

Howard
 
ORIGINAL: DivineE
That's because you drive like a girl[8D]. Get a turbo that'll soon stop you measuring! I can watch the fuel gauge move on full boost[:D].. mind you it still does over 30mpg on a long cruise (when I'm waiting for my friend in his S2)
Click to expand...
... and that, in all seriousness, is one very good reason to keep my S2. Given the way that fuel prices are going, I don't want to be using more of the stuff than I absolutely have to.

Howard, that doesn't sound too far off normal. Alot will be down to driving style and type of driving (town vs. motorway). Stop-start journeys are the most consumptive, and from each cold start it will run rich for a while, using more of the juice. My current driving (infrequent short journeys around town, with it only being started 4 or 5 times a week) reduces MPG to around 18 across a tank.


Oli.
 
You must log in or register to reply here.

Posts made and opinions expressed are those of the individual forum members

Use of the Forum is subject to the Terms and Conditions

Disclaimer

The opinions expressed on this site are not necessarily those of the Club, who shall have no liability in respect of them or the accuracy of the content. The Club assumes no responsibility for any effects arising from errors or omissions.

Porsche Club Great Britain gives no warranties, guarantees or assurances and makes no representations or recommendations regarding any goods or services advertised on this site. It is the responsibility of visitors to satisfy themselves that goods and/or services supplied by any advertiser are bona fide and in no instance can the Porsche Club Great Britain be held responsible.

When responding to advertisements please ensure that you satisfy yourself of any applicable call charges on numbers not prefixed by usual "landline" STD Codes. Information can be obtained from the operator or the white pages. Before giving out ANY information regarding cars, or any other items for sale, please satisfy yourself that any potential purchaser is bona fide.

Directors of the Board of Porsche Club GB, Club Office Staff, Register Secretaries and Regional Organisers are often requested by Club members to provide information on matters connected with their cars and other matters referred to in the Club Rules. Such information, advice and assistance provided by such persons is given in good faith and is based on the personal experience and knowledge of the individual concerned.

Neither Porsche Club GB, nor any of the aforementioned, shall be under any liability in respect of any such information, advice or assistance given to members. Members are advised to consult qualified specialists for information, advice and assistance on matters connected with their cars at all times.

Porsche
Lockton
Pirelli
Officially approved
Oracle Finance
WEX Esso
Collecting Cars
Back
Top