Porsche Enthusiasts Club Forum

Hi All,

Having heard some comments on 928 MPG - I need to work out my average £££

Do I put in unleaded or Shell Vpower super unleaded - £1.33 or £1.40 a litre

As 80% of my mileage is motorway speeds and I am planning 6,000 miles in 2014 what should I budget for please

I have heard from one owner he can get 30MPG and it does not matter if he is doing 60 of 80 MPH

Sounds like £6.37 per Gallon for Super = (6000 miles divided by 200 Gallons @ 30MPG) = £1274

Reading an article on internet, 20MPG sounds more like it, so looks more like £1900 using Super unleaded

I think around town I am looking at 15MPG

Will this apply to S manual, S2 auto or S4 auto - Or is one better or worse.

Am I on the right track please

cheers

Neil

Hi Neil

NOBODY...NOT EVER got 30 mpg from ANY 928 ...lol

My S2 is a daily driver around town... maybe 15 if i drive it like a mouse.... but I dont so around 12 ish....

At Motorway speeds keeping to 70 (which I dont lol) maybe 18 or 19......

ALWAYS put in VPOWER.... the engine WILL run on normal unleaded but it WAS designed for 98 octane.... it runs MUCH better on VPOWER....

S or S2 or S4 makes VERY little difference

I admire you for using it as a DD....just drive it and enjoy it...there is VERY little on the road that can keep up with any 928 (even without Nitrous lol)

But if you are worried about fuel costs you need to buy something without a huge V8 in it lol....

All the best Brett

I agree with Brett, forget fuel when it comes to a 928. It's a V8 and they are thirsty, especially if you want to enjoy all the horses

I had a V6 R32 and averaged 18 miles a gallon, worth every penny.

Hi Neil

My long term average fraction under 22mpg, but very little of this town work. That's better than air-cooled flat sixes manage - combo of air cooled less economical and the LH Jetronic of later 928s much more sophisticated (eg per cylinder ignition adjustment) than 911s of same era.

Use whatever recommended by Porsche. I think early cars specified 98RON. My S4 use regular unleaded 95. The engine management is mapped for this octane rating so there is no advantage in using high octane in this case.

I doubt fuel will be yourost important cost, compared with finding the right car!

I kept a record for the first couple of years that I owned my S2 and the average was 18 mpg (although not a lot of that was motorway driving), so the 32 valve engines and aerodynamic tweaks to the S4 might make it slightly more economical, but the type of journey and driving style would also have a big influence. In terms of auto vs. manual I believe the official figures show that the automatic is more efficient around town but the manual is better on the motorway.

The S2 prefers super unleaded but, as Adrian says, the S4 is intended to use regular 95 octane. If you bought a 32 valve car and then ran it on normal unleaded rather than super unleaded, you would save approx £100 per year (using the figures above).

I doubt whether any of that is significant enough to influence your choice of car (if you were worried about fuel costs you'd buy a diesel).

My philosophy is fill and forget!

As Magnus Walker describes it - "Smiles per Gallon" not Miles per Gallon...

I think my GT did about 20 to the gallon, slightly more on a run, and the S/S2's (auto) around 18.

What a bunch we are, I recorded my mileage too in my S4 auto. I got an average of 19 mpg. It was worth every penny.

Thank you all, I think I got the message now. I think Fun and MPG are not to be confused.

Cheers for 2014 and 928 S4 1989 coming my way.

Neil