fuel consuption

[colin@cjs]

Hi all

I appreciate that fuel consumption isn't the top of most elise owners concerns, but this is driving me nuts!

I have had a type 25 elise s2 a year, for the first 9k miles I was getting 300 miles per fill up which is late 30's mpg. After it's 9k service it changed to under 200 miles per fill up which is late 20's mpg.

Lotus say there is nothing wrong and it must be me, but my driving style didn't change significantly overnight.

I'm just wondering if anybody else has had a similar experience, or can let me know you fuel consumption for their s2 120hp engine, the only modification on mine is the sports exhaust which wa fitted from new.

[Bonce]

Hmmm, that's a hell of a big jump! And high 20s is crap for a standard S2, you should be getting much better. My S1 111S consistently gets 33mpg and I don't pussy-foot around.

Have you verified your mpg by noting down the mileage and litreage at each fill-up? Can you verify your odometer by driving a known distance (i.e. I know it is 12.5 miles from home to office) or by comparing against another car doing an identical journey?

If your calculations and odometer check out then get the emissions tested to see if it's running rich or something. Do you have very sooty exhausts?

[colin@cjs]

I've verified the mileage reading with a gps over 20 miles. I've done consecutive fill ups over three months recording miles and litres. Bell & Colvill assure me that the exhaust readings are normal and that the oil used was the same before and after the 9k service.

My next thought is to get a dyno reading, as presumably any problem causing that amount of extra fuel consumption will also be sapping power, does anyone know what the power should be at the back wheels and also where to get a test done?


>> Edited by colin@cjs on Saturday 3rd April 11:52

[Gfun]

If you have a standard 33 ltr tank - 200 miles would be about 31 to the gallon? (I can just about get 30 ltr in)

But can honestly say I have never managed 300 miles on a tank!

[Bonce]

Very strange. No disrespect to Bell and Colville but I would get a second opinion from another specialist. How about Lakeside Engineering?

I get 220 miles between fill-ups, on average.

[S Works]

Can only comment on an S1 (std apart from Lotus Sport Exhaust) but I'm guessing there can't be a huge amount of difference.

Since I've had it I've filled up 3 times. Each time has been just after it's said REFILL and then switched to 11L, and I've filled it to the click and the guage has said FULL.

Over the 3 times (mixed driving, urban and motorway... "Driving Miss Daisy" and "Days Of Thunder"!) it's returned about 220 miles between Optimax's.

That drop definitely sounds a bit shonky - I agree with Bonce, get a second opinion.

[NJS25]

What fuel & where from?

This can have a dramatic effect. Carbon will build up in the engine, being highly influenced by the quality of the fuel used. This will cause a reduction in economy and performance which would be more noticeable in a new car.

The drop you describe seems a little abrupt, but could be down to a bad batch of fuel.

Worth getting it checked out.

Regards, Neil

[QuinnThe Eskimo]

I've a 200o S1 standard, and I usually get around 220 miles from a fill up not long after the refill comes on so I suppose thats roughly 9 litres of fuel left in the tank.

Hope that helps a bit.

[new111s]

i've got a S1 111s with a exhaust and de cat pipe. The lowest i've seen is 29mpg but that was after a high revs motorway run. Normally I see between 33 and 38 depending on how long i'm stuck behind people!

[colin@cjs]

Thanks for all the feedback.

A 33 litre tank was mentioned, is that for the S1?

My S2 has a 35litre tank.