mpg and where in/around london to get engine tuned/setup?

JAN · Post by **JAN** » Fri Dec 07, 2007 12:56 pm

Two questions really, im getting shocking mpg from my 912. Around town on roughly 5 mile trips, lots of traffic etc i get maybe 12-14ish mpg (lucky to gte 30 miles to £10). Last weekend i went on a run from london to northampton (75mph ish all the way)....cost me £40....so thats around 21 mpg?

Surely thats no right??

What does everyone else get?

Im quite mechanically minded, so dont mind having a dabble myself but dont really want to risk running lean....so either how do I adjust the carbs to lean them off a bit (stock solexs) or where shall i take it thats good in london?

It also doesnt seem to get very hot at all, like not even a quarter up on the temp gauge, so i guess i could advance the timing a small amount and lean off a little? Im pretty sure its running rich.

Cheers for any advice

J.

Ian Gunney · Post by **Ian Gunney** » Fri Dec 07, 2007 1:03 pm

I would guess that mine gets about 30mpg or so on a run

Nige · Post by **Nige** » Fri Dec 07, 2007 1:04 pm

with everything in full fettle and a really light right foot I doubt you get much improvement over those figures. Also remember a tenner barely buys you any jungle juice at the pumps.

stevieboy · Post by **stevieboy** » Fri Dec 07, 2007 1:12 pm

[quote=" jungle juice [/quote]

haven,t heard that for years..

JAN · Post by **JAN** » Fri Dec 07, 2007 2:44 pm

Nige wrote:with everything in full fettle and a really light right foot I doubt you get much improvement over those figures. Also remember a tenner barely buys you any jungle juice at the pumps.

so 12mpg urban and 22mpg motorway is as good as it gets!?

i was hoping for at least 25 or so on a run....

Nige · Post by **Nige** » Fri Dec 07, 2007 3:03 pm

I reckon you can get more, but not massively, things to ensure are in good shape that will/may help mpg are:

valve clearances
correctly setup carbs and linkage
ignition system in good order, plugs, leads, cap, dizzy, timing etc
no fuel leaks - sounds lame but it can ehlp

brakes not binding

hot66 · Post by **hot66** » Fri Dec 07, 2007 3:38 pm

I can get almost 25mpg on a steady 70mph motorway run in my 2.4S, so I'd have thought a 912 would manage that .

Country roads @ full chat can get into single figures though

Ian Gunney · Post by **Ian Gunney** » Fri Dec 07, 2007 4:56 pm

put another way, Paul Calderbanks 911 used a lot more fuel to CLM last year than my '12

If all the mechanicals are in good condition, you should get 30 on a run.

Flat 4 · Post by **Flat 4** » Fri Dec 07, 2007 7:39 pm

I agree with Ian, if all is well you should see late 20s to early 30s on a run...last time i went to Le Mans we were getting about 28 sitting at 80mph + all the way.

912uk · Post by **912uk** » Fri Dec 07, 2007 8:57 pm

25 on av.. at best 28..

louis356 · Post by **louis356** » Fri Dec 07, 2007 9:53 pm

£18 for 130 miles everyday mostly M25

Don't know what is in mpg - what does a gallon cost these days?

JAN · Post by **JAN** » Mon Dec 10, 2007 9:13 am

any adivce as to where to take it for a tune?

or info on tuning the stock carbs myself?

ta.

Nige · Post by **Nige** » Mon Dec 10, 2007 9:45 am

do the easier stuff first, make sure the igntion side of things is spot on, valve clearances, plugs, timing, etc. Leave the carbs until last if as you'll only tune the carbs to compensate for everything else and that won't neccesarily improve MPG.

Knackered plugs, leads and cap with valve clearances out of whack won't improve by having you're carbs 'tuned' Elimate everything else and then do the carbs.

Do 912 engines have a thermostat for the fan housing flaps? If they have been removed it'll take longer for the engine to warm up, that won't help mpg either.