Fuel Consumption

[jamesogt]

Not something really to worry about I am just wondering what you consider average!

Sheffield-Cleethorpes-Hathersage 155 Miles, high percentage motorway and out of the 3 hours maybe 30 mins traffic, and 20 mins country roads.

17 MPG in a 450 Chimaera... Sound about right?

Cheers

[db418BHP]

I would be dissapointed with under 20 mpg on that run.

[phazed]

Journey to the ring, sensible speed on motorway, sightseeing speed on scenic roads, 4.6 = 28mpg.

[LongBaz383BHP]

I did 239 miles yesterday and still got a quarter a tank left. Motorway all the way. About 25 mpg

[pearly]

I consider getting 160 miles out of a full tank normal, on my main journey 26 miles a day (20 miles A roads and 6 in the town). That's in a 4.3 which I do warm up first (out of the blue) and I do have a slightly weighty right foot, what can I say, but I love the sound track

[Goaty Bill]

17/18mpg
Town 17/18mpg.
Motorway 17/18mpg.
Never anything other than 17/18mpg.
I've checked it every couple of years; 17/18mpg.
The only time it's different, is when it's on a flatbed truck.

[carsy]

Looks like the aftermarket ecu's can be mapped to give considerably better economy.

[db418BHP]

carsy said:

Looks like the aftermarket ecu's can be mapped to give considerably better economy.

Seems that way upto now.

MS2 on a 330 bhp 4.6
I got 28.8 mpg on a 200 mile drive in under 3 hours.

[Robert Lees]

I reckon that's not bad. my 450 has mark Adams tornado chip and I reckon my average is about 18-22. Probably on that run would be nearer 22 than 18.

saying that I have taken the car out 3 times last week for 30 minutes blasts along country lanes and the gauge hasn't budged... Should I be worried,, or pleased

[Graham]

17mpg! i get more out of a range rover than that !!! my 4 ltr used to average about 26 ( track use excepted)

[finestjammy]

I wish I had some clue as to the consumption. A combination of an extremely ambitious speedo and no trip meter (93 car) means I haven't got a clue. Probably best that way though

[KateV8]

carsy said:

Looks like the aftermarket ecu's can be mapped to give considerably better economy.

Agreed. On a motorway run (with 14CUX) I'd struggle to do better than 20-22mpg, now with Canems same journey would return 28-30.

[Sardonicus]

Got 28 (so do many others) on a run with my old Lucas CUX ECU if your getting low 20's on a run and staying below 80mph then the thing aint fuelling correctly, to the OPer if your getting 17mpg then you have problems that figure is urban IMO

Edited by Sardonicus on Monday 22 April 17:14

[KateV8]

KateV8 said:

carsy said:

Looks like the aftermarket ecu's can be mapped to give considerably better economy.

Agreed. On a motorway run (with 14CUX) I'd struggle to do better than 20-22mpg, now with Canems same journey would return 28-30.

Mmm, should qualify by saying I couldn't vouch for the accuracy of the fueling beforehand, that said the engine ran fine under Lucas. It was the eternal idle issues that I eventually lost patience with.

[Trevor450]

I get more out of the Chimaera than I do out of my daily driver. Seriously, I think I get about 22 on a long run but it never seems to get much below 20 but I have stopped checking. My daily does 16-18 in comparison but can do 28-30 on a long run.

It did 5mpg on the track! Emptied a tank in 50 miles or so I think.

[ChimpOnGas]

Sardonicus said:

Got 28 (so do many others) on a run with my old Lucas CUX ECU if your getting low 20's on a run and staying below 80mph then the thing aint fuelling correctly, to the OPer if your getting 17mpg then you have problems that figure is urban IMO

Edited by Sardonicus on Monday 22 April 17:14

I regularly saw 28mpg on a run on the Lucas 14CUX & distributor, the best since changing the engine management system has been 30mpg, but there a many other benefits that came from the Canems.

So there's either something amiss with the OP's car, or his calculations?

I'm now getting the cost equivalent of 38mpg on LPG with no performance loss, with over 40mpg to come after some more attention to the light load cruising area of the LPG map.

Even driven as TVR intended, I simply can't get it below the cost equivalent of 35mpg, and believe me I've tried.

This weekend I did over 300 miles, masses of wide open throttle acceleration, two or three sustained runs exceeding 120 leptons.

Result?, once again the cost equivalent of 35mpg, I'd be lucky to see 22mpg on petrol driven the same way.

I concluded a long while back that the only way to meaningfully improve the cost per mile in these cars, is to go with LPG at £0.74p per litre.

However, the OP & others that aren't seeing 28 mpg on a run need to find out what's wrong with their car.

28mpg should be your target, it's a perfectly achievable & realistic one.

[jamesogt]

It does have plenum, sleeved exhaust and upgraded chip. I need to get its paperwork folder out though as I didn't put the chip in.....

[2 sMoKiN bArReLs]

My 450 averaged 22 mpg

My 500 averages 22 mpg

[Meths]

Wifey averaged 29mpg on the run to Germany on decatted 4.0.

Noticed a slight increase in mpg since removing them.

[QBee]

My 4 litre was high twenties
My 5 litre is around 20 mpg mixed driving including a lot of motorway, running in. Develops a hole in the tank on the track!