M p g

[ronnie]

Just done a round trip tonight of 60 miles and after a refill of the tank the moggy clocked about 34 mpg I'm not complaining about that but how does that compare with you guys

[bmcecosse]

Pretty much what you can expect. Some claim 40+ but I have never seen that.......

[ronnie]

That was mostly country road driving about steady 55 and about 20 per cent town driving

[mike.perry]

The fuel tank was brimmed full before and after the run?
The fuel was converted from ltrs to galls?
The mileometer was checked for accuracy?
If you are bothered about the fuel consumption, you are not enjoying the driving

[liammonty]

My 1098 Traveller managed 45 mpg on a 650 mile trip to the Massif Central in France which we did in one go- speed had to be kept to 55-60 mph max after the main bearings started grumbling due to thin oil in the 35 degree heat when I'd been pushing it too hard! That was exceptional though, and I don't think you'd ever get much more than that.

Normal driving, 35 mpg is pretty much what I get. My 948 cars have been the best- better than the 1098, and also better than the 803 I had, which only became economical after I ran the big ends and didn't drive it any more!

[ronnie]

It's called curiosity mike !! Love driving the car :0)

[JOWETTJAVELIN]

My 948 cars have been the best- better than the 1098, and also better than the 803 I had, which only became economical after I ran the big ends and didn't drive it any more!

Yes 803 fuel consumption is not as good as you'd expect. Couple this with only a 5 gallon tank!

For a 1098 34mpg is decent, but I manage 35mpg and about 40-4mpg motorway in the Allegro 1300 (1275 engine).

It depends how good you are fiddling with the carb (keeping things reasonable) and how stringent you are about checking, as Mike says, you need to brim the tank, write down cost and quantity of petrol and convert to gallons, odometer reading, then drive and nearly empty it, fill up, record all the details again and then you'll get your figures (btw this really isn't as hard as it all sounds).

[chrisd87]

If you want a truly accurate figure then you also need to find out how fast/slow your odometer is. I recorded my consumption over several thousand miles, and found it to be just over 40mpg (car is a standard 1098).

[mike.perry]

[quote="chrisd87"]If you want a truly accurate figure then you also need to find out how fast/slow your odometer is.
I did mention that only I called it a milometer.
As said, the smallest engine option is not usually the most economical as you need your foot screwed to the floorboards to get enough speed to get up the hills, and even then you will probably need a downchange, whereas the larger engine will allow you to climb gradients on a light accelerator.
Of course if you use the full potential of the larger engine then economy will suffer
This is also known as stating the bleedin' obvious

[bmcecosse]

[lambrettalad]

had my 1098 for a year now and i've averaged 37 mpg over many measurements and I ain't gonna do any more cause its ok and now i can neigh be bothered 'cause its fun even if it was 20 mpg

[ronnie]

These cars give you hours of fun amusement and endless self achievement and it wouldn't matter what it does to the gallon but nice to know its mid thirtys . If it was only doing about 20mpg then something is obviously wrong

[daveyl]

I have a 950 (now 998) with flat top pistons and 12G295 head. Bigger carb/filter/exhaust etc. I have driven it very sensibly and still only get 32mpg.
BUT it's running with too low (high?) a ratio diff at the mo (3.6:1). Making it too 'tall' in first gear and wasting fuel me thinks. So that job is first on the list. I may put a smaller valve head on it and give that a go if there is no improvement. Much fun to drive it as is though!

[bmcecosse]

Where did you find a 3.6 final drive ?? Best I could find is a 3.7... My 1098 with 940 head (so much bigger valves than the 295) and carb etc can be encouraged to give 40 mpg IF I drive at no more than 50 mph. Sadly - I rarely do........ So I wouldn't change anything - except the carb needle. What's in it now? What colour are the plugs after a good run? And has the ignition timing been 'optimised' ? Has the 295 been skimmed to give a decent CR ?

[daveyl]

BMC, I'm still running around with a Marina axle, which is 3.6:1. Soon to be 4.1 ratio as it has Toyota a 5-speed box. It's the first gear on this box that makes it a bit too 'tall' for my little engine to get the full revs from a standing start. Although, it would be perfect with a Minor or Midget 4-speed box.

The head has been skimmed (2mm) and has 200lb of compression across the cylinders (too high perhaps?). It does seem to run better on the higher octane fuel. I have used the method of moving the distributor in stages to find the point of it 'pinking' and 'not quite' so.

The carb is a Hif38 with a AAA needle and a KN filter. I have adjusted the mixture by trial and error. With the engine hot and the plugs 'black and sooty' as a starting point, clean the plugs and turn the mixture screw a quarter of a turn to lean it off and take a quick run and check again. Have you any suggestions on a different needle?


It runs really sweetly as is though. And it sounds fandabbydozy!

As regards fuel economy, my 9 mile journey to work is all in peak traffic with a hectic 3 mile 'dash' on the motorway, having to cut across 2 lanes of high speed traffic (no one will let you change lane at 50mph!) so I'm probably asking too much of it anyway.

[bmcecosse]

The compression sound great - yes use the better fuel - it will give better economy to balance the cost. You need a better cam in that engine - even a 1098 cam would be good. MG Metro would be better. I use the AAA needle and my plugs are almost 'white' .