Miles per gallon

[MRGT]

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

 

[zcacogp]

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[].. mind you it still does over 30mpg on a long cruise (when I'm waiting for my friend in his S2)

... 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.

 

[Fat Albert]

I am hoping that my MPG will improve now that I can drive with the lights down and the engine at a reasonable temperature, but I have been struggling to get passed 275 miles on a tank of 98/99, it works out at low 20s, mine does need a good service and replacement of rotor arm to sparkers, and I also admit to the very ooccasional wearing of heavy shoes[] I got up to 30ish mpg last year when being sensible on a run

 

[MRGT]

Oli, my commute to work is 32 miles of very quiet dual carriageway with 1/2 mile or so at either end, at a steady 65-70 mph I would expect to see better than 28mpg, given that most people report over 30 on long gentle runs. My old Lux which I had many years ago would regularly get 33-34 on a similiar run and the the 16V's are suppossed to be slightly better (according to the handbook). It just has me slightly concerened that something isnt right somewhere.

 

[pauljmcnulty]

Oli, my commute to work is 32 miles of very quiet dual carriageway with 1/2 mile or so at either end, at a steady 65-70 mph I would expect to see better than 28mpg, given that most people report over 30 on long gentle runs. My old Lux which I had many years ago would regularly get 33-34 on a similiar run and the the 16V's are suppossed to be slightly better (according to the handbook). It just has me slightly concerened that something isnt right somewhere.

I get noticeably less from my S2 than my Lux. I'd think an S would be likely to be worse than a Lux as you have to rev it so much to get the power out of it. I'd not panic about getting a little under 30 from it.

 

[JamesO]

My 2.7 did over 400 miles to a tank cruising at around 90-100mph (where legal) on super unleaded, although that was without the AFM using microsquirt. Before I monkeyed with the fuel and ignition system the economy was still pretty good, but I cant say I ever bothered to measure it. No idea what the 3.0 will do as i'm mapping it which is a good way to waste fuel.

 

[Super_Marv]

My 968 CS does low 20's around town and what not. On a decent run, without much traffic, it has been known to break the 30mpg barrier, if such things are considered important? []

 

[DivineE]

ORIGINAL: zcacogp ... 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.

That is one big one in favour of the S2 under normal driving the18-25mpg short trips and 30mpg long run I've known from my various 951's is not too far wide of the mark but keep that turbo spooled hard and it really can drink at a silly rate! I counter the argument in my mind with the old 'Well if fuel is that expensive I'd better enjoy it to the full!' argument ...but honestly it does make me wince when the pump clicks over the £100 per tank mark! Some petrol stations only let you put £70 at a time in so you have to pay and then carry on!! Silly world we live in now.

 

[david924s]

ORIGINAL: A9XXC 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

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

My early 1986 924S which has the same engine as the early 944 had a label in the petrol filler stating 95Ron Unleaded not 98Ron.

 

[barks944]

The lux's will run fine on 95. Afaik they were mapped for very poor quality fuel. I did seem to get better MPG on high octane but I could never think of a reason why.

 

[944 man]

ORIGINAL: david924s My early 1986 924S which has the same engine as the early 944 had a label in the petrol filler stating 95Ron Unleaded not 98Ron.

Remember that all 924Ss, apart from the final production year, had a unique low compression engine. Only the 1988 924S had an engine shared with a 944. Simon

 

[awattam]

I get somewhere around 25 doing my 4 mile commute. On a decent motorway run it's around 30. 36 is my best with a relaxed run to edinburgh. How big is the tank on an S2? From the light I put in about 60-65 litres to fill it but I'm not sure how much if left and I've never dared to find out!

 

[Mike_Pollock]

David - not quite the same, the first 924S s were 150bhp versions of the 163bhp 944 one, and the last ones used the 163nhp engine from the oval dash cars which had different C/R and lots of other minor changes and ran on 95. It is only the square dash 944s that need 98 as they run 10.6:1 the others all run 9.6:1 Mike

 

[DivineE]

ORIGINAL: A9XXC David - not quite the same, the first 924S s were 150bhp versions of the 163bhp 944 one, and the last ones used the 163nhp engine from the oval dash cars which had different C/R and lots of other minor changes and ran on 95. It is only the square dash 944s that need 98 as they run 10.6:1 the others all run 9.6:1 Mike

Well you learn something new every day! I never knew the compression got lower? I'd have thought in their search to improve fuel consumption it would have gone up!

 

[Diver944]

ORIGINAL: awattam How big is the tank on an S2?

It should be 80 litres when totally brimmed. You can normally squeeze in a good 4 or 5 litres once the auto shutoff on the pump has clicked in. The low fuel light is supposed to come on when you have 8 litres left, enough for a good 50 miles at a steady cruise. I have occasionally done over 30 miles after the light has come on (make sure your light works before testing this [] )

 

[Mike_Pollock]

Worth bearing in mind that the square dash cars have alot smaller tank - 67 litres I think - when you're calculating range! Mike

 

[AndrewS]

Here are some fuel figures that I achieved in both my longer term 944 Turbos Track: 6-7 mpg Town (stop start, driving between roundabouts - no long stretches of road) 14-19 mpg Hard & fast motorway driving 21 mpg Real Gentle constant speed 26 mpg (A roads, Motorways) Current CV8 Monaro averages 14 mpg round town and will do over 30 mpg on the Motorway (8 mpg on the track). I only mention this is it demonstrates how much fuel economy varies acording to the way the car is driven and the roads its driven on. My recent BMW 735i was very similar to the Monaro - the trip computer making fuel consumption very evident. Regards, Andrew

 

[david924s]

ORIGINAL: 944 man

ORIGINAL: david924s My early 1986 924S which has the same engine as the early 944 had a label in the petrol filler stating 95Ron Unleaded not 98Ron.

Remember that all 924Ss, apart from the final production year, had a unique low compression engine. Only the 1988 924S had an engine shared with a 944. Simon

I agree the 1986 924S had only a 150bhp 2.5l engine but this was 9.7:1 with the later 1988 model being 10.2:1 whereas the early 944 up to 1986 were only 9.5:1

 

[tref]

Thought I'd resurect an old thread rather than end up covering the same ground again... I believe I have noticed something interesting - when you think about it, not surprising, but significant when we talk about MPG. I reckon that in general driving (in my case a mix of highish speed motorway/dual carriageway, country lanes, and pure urban pain), I see about 10% difference in fuel useage summer to winter. Anyone else noticed this effect? Things like lights drawing power, increased drag with the lights up, rear demist and heater, are obvious, but I suspect lower engine temperatures are as, if not more important.

 

[Jonny944CS]

I also see around a 10% drop Tref. A cold engine requires significantly more fuel than one at normal operating temp. Higher internal friction, less stable combustion and fuel vaporisation must all be overcome. Therefore I would say that temperature has the largest effect, particularly if most of your journeys are short-medium distance. Block heaters and radiator blanking plates seem to be common in colder countries. For other factors, certainly electrical loads (I'm interested to see how the Nissan Leaf's range is affected by a harsh winter), low tyre pressures, snow induced traffic jams, etc etc. More aerodynamic drag? I'm thinking that ought to be offset by the denser, more oxygen rich, air entering the engine.