2.5 vs S2 fuel consumption

[dann944]

Now, ive heard that the s2 has improved fuel economy on the Lux, seems strange as its a bigger engine and more valves ?

 

[Peter Empson]

I've never been that worried about fuel economy, but I really don't think there's much, if anything, in it. I have compared the two engines in the same car and don't recall noticing any major change. However I do tend to use all of all the performance when conditions permit [] just pottering about might be quite different, but what's the point in that?

 

[Tam Lin]

Around town there's not much in it. At motorway cruising speed, the S2 16v uses less by about 15%. Both my 8v and the 16v were chipped, so the fuelling may have been slightly non-standard.

 

[dann944]

some times i like to drive round town at 15mph

 

[Mike_Pollock]

Posing huh!

Do the Police pull you for kerb crawling!

Mike

 

[dann944]

no no they pull me for just being in a porsche.....

 

[Mike_Pollock]

They shouldn't be able to catch you in a Porsche!

Mike

 

[pauljmcnulty]

I get less in the S2 than the lux, probably 2 or 3 MPG. I don't worry to much...[]

 

[mr brightside]

My 924s is chipped and will get to Bristol on £28 of Optimax at 80-83 mph, can't be ar**d to do the sums! I live in Leeds.

 

[Mike_Pollock]

Mgp wasn't and isn't on the list.

Mike

 

[PSH]

Not sure about the S2 figures but I can give you the official Porsche figures from their 1986 handbook between the turbo and the lux


urban driving

turbo: 22.8mpg
lux: 24.8mpg

56mph

turbo: 44.1mpg
lux: 40.4mpg

75mph

turbo: 32.1mpg
lux: 32.5mpg

[]

Pete

 

[Mike_Pollock]

Thanks Pete

No point in me driving at 56mph then!

Mike

 

[cococola]

I get an average of 28-32 mpg in my 2.5 lux

 

[ChasR]

ORIGINAL: PSH


Not sure about the S2 figures but I can give you the official Porsche figures from their 1986 handbook between the turbo and the lux


urban driving

turbo: 22.8mpg
lux: 24.8mpg

56mph

turbo: 44.1mpg
lux: 40.4mpg

75mph

turbo: 32.1mpg
lux: 32.5mpg

[]

Pete

Here's a couple more to add onto that list:

Simulated Urban Driving:
S2 Cat: 19.8MPG
S2 Non:20.2MPG
Turbo Cat:21.2MPG

Constant Speed Driving 56MPH:
S2 Cat:38.2MPG
S2 Non Cat:41.5MPG
Turbo Cat:39.8MPG

Constant 75MPH:
S2 Cat: 31.0MPG
S2 Non:33.6MPG
Turbo Cat:30.4MPG

I would take mine with a pinch of salt considering my engine has suffered from a seized piston. Normal driving (in town, on dual carriageways) I will get 150 miles from £20. On a run, this figure does improve. Of course being an early S2, mine is decatted. Driven mostly in town I will hit 25MPG.

I wonder if the differences in MPG noted are down to ones with a cat and without.

 

[billus99]

I would maybe be calculating mpg by now, but dont know where the little button is to zero the trip, any ideas?
Also, I'm sticking 97RON in my new 944, just noticed the sticker inside fuel flap that says 95, any advice?
Thanks
Andy

 

[pauljmcnulty]

I would maybe be calculating mpg by now, but dont know where the little button is to zero the trip, any ideas?

Many forums would be laughing their little socks off at such a noob question! [][][]

Right hand centre vent in the dash is a fake, the button is the trip reset. Don't use it whilst moving, the whole linkage is brittle plastic and may break.

My S2 runs better on super unleaded, but I suspect it's chipped. I used to run my Lux on super as well, it might be my imagination but it really seemed happier.

 

[ChasR]

Unless Oli's is also chipped I believe his runs better on the higher RON fuels too.

 

[Mike_Pollock]

I've been running mine on 97, occasionally 95, but Friday night I filled up with Shell 99 (whatever they call it) as I was going up to Lemons Dyno Day and was amazed at the difference!

So smooth with very sharp pick up, it felt really good. So good, I thought I'd blown the head gasket on the way up! Well it was very early and the roads were empty!

I've no idea of the mpg I get, but it feels poor around town and pretty good on a "sensible" run.

One point from the dyno day, Steve (Proprietor of Dyno Demon) reckons that the "super juice" is only good for a few days!

Mike

 

[pauljmcnulty]

Unless Oli's is also chipped I believe his runs better on the higher RON fuels too.

I can't remember if his is. Mine has no record of a chip being fitted, but it has no noticable step in the power throughout the rev range. I'd like to know in case I should inform the insurers, but I won't risk breaking anything in order to check.

 

[ChasR]

I put the step down as a characteristic. Unless mine is also chipped (with the cup wheels, mirrors and braided brake lines, it's quite possible). IME, a number of 16v engines do this . An 8v will feel 'flatter' in comparison.

ORIGINAL: dann944

Now, ive heard that the s2 has improved fuel economy on the Lux, seems strange as its a bigger engine and more valves ?

Two sides of the coin really. IME, if you floor larger engined cars, they drink the juice like George Best. If you drive normally, MPG (up to a point in engine size) stays around the same, possibly improving on motorway runs due to the engine working less.

My Ford Ka 1.3 did 37MPG tops on a motorway, and around 31 normally (that was a newish car). Focus did 35MPG normally, going to around 38MPG on the motorway. Peugeot 306 GTi-6 did 31-33MPG normally, and I hit 39MPG (70-75MPG) on the motorway a few times and around 34MPG going a little quicker. Porsche hits early 30s on the motorway IMO. Town driving kills its MPG. The Non-PAS Ka I had for 2 weeks did hit 40MPG normally and probably near 50MPG on the motorway.

On paper, the Ka was meant to be the most economical, followed by the Focus, the Porsche and then the Peugeot.