Fuel Tank Capacity.

[sawood12]

The turbo manual reckons 44mpg at a steady 60mph- and I can believe it. I've had about 35mpg at a steady 80/90 on a long run (keeping up with the flow of traffic of course). If you're a believer of the current environmental propoganda then that is a truly planet saving level of fuel economy with the stuff out of the exhaust being much much cleaner than the filth diesel cars chuck out. Unfortunately the so called planet savers would prefer to see us all slow down rather than travel at the most economic speeds.

 

[zcacogp]

Damon,

A point of clarification - you are sure you did work on UK gallons? You did say so in your post, but a US gallon is a chunk smaller than a UK one, and therefore the MPG will be less.

I have seen about 32.7mpg at the most on a tankful of normal unleaded in my S2. If Boy Smith is to be believed, you should be able to do better than that. (Smaller engine - 2.5 as opposed to 3.0 - and higher drive ratio should all be in your favour.) Tyre design and pressure can make a difference, as can the time since it was last serviced, the oil choice (thicker = less economy). I would have thought that wider tyres would adversely affect things as well, as the rolling resistance would go up. As can having the window open and a million other little things. (You did have the handbrake off, didn't you? [:-] )


Oli.

ETA: Scott, anyone who believes the environMENTAList line is nuts, in my humble opinion. The earth hasn't got any warmer since 1989, which it should have done as we are (geologically speaking) coming out of a mini ice age. Don't forget that 20 years ago, the same 'scientists' were telling us that global cooling was a major threat to mankind and were planning to set off some atom bombs in the polar regions to warm the planet a little ...

 

[appletonn]

Errrm,[8|] I've not seen over 24mpg yet, although in my defence M'lud I have had to set my boost levels up and errm check the handling of the car and errrrm...

Hopefully, on the cruise to Le Mans, I can keep it off boost long enough to see some more sensible figures..[8|][]

 

[edh]

I think mpg tails off quite badly once you get over 100 Nick []

- I can use a tank & a half on a dry trackday []

 

[sawood12]

I find the car is designed for best cruising (though not necessarily most economical) at around 80 to 90 mph. This puts you right at the start of the boost zone, so you can give it a squirt of throttle and get instant accellaration, and the car holds it's speed with little or no throttle. I think this is quite a good balance of economical driving (as I said i've seen around 35mpg at these speeds) and getting to your destination quickly. I may be able to get 44mpg at a steady 60 (never tried) but I just can't sit at 60. You're way below the boost zone and don't feel like you're making quick enough progress.

 

[Black_JPN]

Wow, here's me thinking I was doing well. Cheers Paul, now I think I have a problem with my car!!

Oli - yes, handbrake was definitely off.. You're right though, I think my calculation may have been wrong. Assuming 0.219969 UK gallons to a litre then I got 32.991mpg on the way there. Which makes things worse!

I just calculated the return which was a tad more spirited and included some rather blissful overtaking whilst journeying between Grasmere and Keswick while we were up there, also a brief dalliance with a Ferrari 456 on our way home and several "how dare you approach me that quickly from behind and ride up my chuff" then bury the throttle type moments. Anyway for my return leg I managed 29.53mpg.

Prior to this jaunt I had only done small trips, mostly using boost so it was pleasing to see just how much mpg I could squeeze out. However it is no fun without boost. Scott you're spot on with the 80-90 cruising speed, it was lovely to know the boost was on tap if and when it was needed. The car sits so well with the throttled being gently tickled at this speed.

I actually have a very 'spitty' exhaust, it spits out lovely moist black soot when idling so this may hint at a problem (running rich?) as to why I'm not getting the refuted 35mpg or even 44mpg! (always wondered what the 44 in 944 stood for..)

 

[zcacogp]

Sunroof's out in the piccie - that'll knock a reasonable bit off the MPG at high-speed. Seriously.

Having the lights up is meant to make 1mpg difference at around 70mph.


Oli.

 

[Black_JPN]

ORIGINAL: zcacogp

Sunroof's out in the piccie - that'll knock a reasonable bit off the MPG at high-speed. Seriously.

Having the lights up is meant to make 1mpg difference at around 70mph.


Oli.

I can believe it, that was for a 15 mile jaunt to Beatrix Potter's house! The rest of the time it was in and sealed. Lights were always down too.

 

[zcacogp]

Ahhh .... Hill Top. Lovely place. My late grandmother was very close friends with Beatrix Potter, and the family still owns much of the land in the area.

A truly, truly delightful part of the world. Who cares about MPG when you have scenery like that!


Oli.

 

[appletonn]

Mine spits out moist soot too at idle, but only when cold - once hot, it only appears to run slightly rich when boosting hard, according to my Dad who was following me on the way to Oulton Park the other week, who said that he could smell the 'richness' and there was a tiny puff of black smoke when lifting off to change up.

However, if yours is running rich at idle and you are still getting 29mpg at a cruise, then there can't be much wrong with it!

I dream of getting 29mpg.... (to be said in Pythonesque "get up in the middle of the night 2 hrs before you went to bed, lick t'road clean..." sketch type of voice!)

I intend to get a better feel for the real world MPG on the way down to Le Mans - 80'ish on the motorway to Portsmouth should give me a better result than the 23mpg from just playing around [8|]