12mpg - 4.0 Non HC

[Jon Brown]

I don't normally calculate MPG, just put petrol in and drive but as the car used 3/4 of a tank since friday and havn't gone very far this weekend (120 miles max), so roughly 11-13 mpg.

Is that right?, admitidly roof was down on most of the journeys and would say about half of the above was motorway and the rest was country roads but not thrasing it or anything.

Something must be wrong with the car surely or are they all this bad?

[Milky400]

best way to find out is fill up, do a good half a tank, fill up again an check the milage against litres/gallons used mine will do 250-300 to a tank, but who cares

[K4TRV]

As he says above - full tank to full tank then calculate!!

Both the temp gauge and the fuel gauge have a lot to answer for in terms of accuracy. Just use them as an indication, not to give a diffinitive reading!!

HTH

[JR]

Should be about double that. Your stated mpg is track day stuff. Max is low 30s on a steady m/way cruise.

[SILICONE KID]

Milky400 said:

best way to find out is fill up, do a good half a tank, fill up again an check the milage against litres/gallons used mine will do 250-300 to a tank, but who cares

You must have a different engine fitted, i got 130 miles out of a tank..I was speaking to a guy at Thorsby who claims he gets 32mpg out of his MG RV8 ..you must have a standard lump

[Milky400]

SILICONE KID said:

You must have a different engine fitted, i got 130 miles out of a tank..I was speaking to a guy at Thorsby who claims he gets 32mpg out of his MG RV8 ..you must have a standard lump

Indeed i have got a standard lump, Problem? i thought that is what the OP was asking about, none of this me mega squitts stuff, which gives a 100 MPG and 300 extra Horses

Edited by Milky400 on Tuesday 3rd May 16:30

[Chimpafrolic]

I agree with Milky400 here.

For example don't assume if the gauge says half the 12 gallon tank is used you have burnt 6 gallons.

At best the fuel gauge is a bit hit & miss.

For information my 4.0HC Chim delivers:

Town: 22mpg

Mixed driving: 24mpg

Motorway (80mph): 27mpg

Some say they get 30mpg or more!!!

But the very best I have ever seen is 28mpg.

I have had 320 miles out of a tank but to be safe I typically fill at 250 miles from full.

Edited by Chimpafrolic on Tuesday 3rd May 16:30

[Jon Brown]

My car is standard, will do a tank to tank run next and also get the emissions checked

[SILICONE KID]

Is it a 50 litre tank ..?

[andy-w]

FWIW - 4ltr HC and i am getting about 18 mpg but i use it daily to and from work which is about 6-7 miles from my house so it is doing most of its miles cold...last mile and it is up to temp...!!!

[JR]

Chimpafrolic said:

Motorway (80mph): 27mpg
Some say they get 30mpg or more!!!
But the very best I have ever seen is 28mpg.

27 at 80 => about 31/32 at 70...

[ph1l5]

I did 300 miles (motorway) a few weeks ago 3/4 of a tank used, right till the last 10 miles when I started to chase a pair of Lotus suddenley I was almost out.

[Chimpafrolic]

JR said:

27 at 80 => about 31/32 at 70...

I can honestly say I have never driven any significant motorway distance in my TVR at a steady 70mph.

I just couldn't do it, must feel like you are standing still, 80 - 85 feels like the minimum natural cruising gate in my car.

At 70 you get just get caught up with the muppets in the slow lane, then end up doing the slow to middle and back to the slow lane dance.

I feel safer in the fast lane at 80-85 keeping an eye on my mirror for the license loosing speed freaks approaching from behind.

Any how I used to measure the MPG religiously (hence my figures) but I found it took the fun out of driving.

As long as the economy is not off the scale poor (indicating something is wrong) I am happiest re-filling when it gets down to the last quarter on the gauge.

Fill > Drive > Smile > Fill Again

[walt762]

I don't keep a close eye on it but I get approx 18-24 in my 500 roughly 200 miles to a tank with a bit in hand.
I think your 12-13 is very poor unless you were hamering it.
I would get the timing/emissions checked & also ensure it is firing on all cylinders as they will run no trouble with one cylinder down.

[Chilliman]

What Chimpafrolic said

Edited to add what Walt said is about what I get mpg... not that I've measured it, it's an off the cuff calc... Modern cars are amazing with mpg returns... but that's latest tech euro boxes for you.... the Chim engines are 1950 (1960 ?) vintage... bought by rover when buick didn't want them anymore.........they're simply not fuel efficient motors.... (but F**k do they sound great )

Edited by Chilliman on Tuesday 3rd May 19:37

[potato muncher]

13.5 MPG around town, 24 MPG on a run. A rather fast run as it was my first blast, I do not care though, smiles of fun.

[Jon Brown]

Not had a chance to get a gas tester on this but I have checked one of the plugs and it was rather carbonised.

Standing behind the car on idle it is rather intoxicating, being that there are barely any sensors on these engines I guess its probally a lamba sensor thats dead. If it was only on one side would the plugs on both banks be carbonised or would it just be the one side?

So do I pay £100 to get a dianostics run? (austec racing) or do I buy a new lamba sensor for £100 and try that?

[dog man]

I think the bible gives you quite a basic way of testing the labdas. Or pop it on your local MOT man's gas analyser if you can?

[tonys]

As others have said, you need a brim to brim check; using the gauge is not very accurate. Still, probably better than someone I know who used a bit of bluetack on their gauge to see how far a gallon got them (student days, of course).

[bobfather]

Are you using 99ron? 95ron unleaded will return less MPG than 99ron. It wouldn't cause the low numbers you are discussing but I'm guessing most of the responses here are related to 99ron fuels