Talk Morgan Forums Community The Malvern Arms Fuel economy

I always fill the tank to the top and always reset the 'trip' to zero.

When the trip reads 250 miles I start to look for a petrol station. Dividing the 'trip' milage by the amount of petrol needed to refill the tank gives me the mpg.

I confess, I don't do it every journey, must be the crocodile in me.

My 97 +4 usually does short fast runs to say Tescos on a Saturday = 6 miles.

The average over 6 years 28.5, avg - SD = 34.8, avg + SD = 32.3.

Longs runs get around 34-36 and long slow runs I have hit 40-41.

My 94 Zetec 4/4 gave similar numbers but was used to commute daily c 80 miles from Bucks to Camberly & back. Avg 29.9, Avg -SD 28.1, avg + SD 31.8 over the 3 yeara I owned it.

My '92 CVH efi gives about 38mpg on average.
I have never done a full definitive test - fill tank,drive til refill,note miles done and fuel added,calculate mpg - but close to this only.
Its a standard engine with a K&N fitted.
I have just replaced the air feed pipe as it was melting due to being routed close to the exhaust downpipes. The new pipe is covered with insulation. Hopewfully this will reduce the air temp a bit and may give improved performance,( but noticeable?).
My usual attitude is to fill the tank and drive with a smile, filling up when needed. I have drained ghe tank due to muck in petrol and made a note of the gauge reading with just over 1 gal in the tank so have an more accurate(?) idea of remaining fuel.
I may extend the insulation under the bonnet as the airflow is routed over the top of the engine so the filter airbox and rest of the tubing may get insulated.These do feel warm after a run but I don't know if there will be a measurable performance improvement. The wing area also feels warm after a run as the cat is close to it so this may get the treatment at some stage.
Last saturday we were on a run and a short discussion cropped up re exhaust wrap. This may be another route. I don't see any problems with it as the wrap will get hot and be permanently dry. I don't think the comments re it causes manifold rusting can be that much of an issue if at all.Manifolds rust anyway unless treated with coatings or manifold paint.As for heat effects - the insulatin properties will SLOW DOWN cooling and thus maintain the metal microstructure . This insulation promotes an annealing type process rather than a "normalising" faster cooling rate in air. Takes me back to my Metallurgy days!

My 3.7 Roadster is averaging 32/gallon, which I'm quite happy with. At the start of the fuel protests a few years ago, I got caught out with half a tank in my Rover 75 & nowhere to fill up
By using every trick I could think of, I managed 50/gallon . I was impressed. Never done it again, mind...
Ian

32mpg from a 3.7 roadster. That sounds very good indeed.

in passing.............I have noticed in 3 separate cars that filling with super petrol gives significantly more mpg. I'm led to believe that the engine compensates for poor fuel (to stop pinking) so maybe it's cheaper to fill up with more expensive fuel. Anyone an expert?
Nick

I have heard the same.
An old neighbour of mine had a Ford Escort 1.4 (last model before the Focus). He told me his fuel consumption was significantly less using 97 Ron unleaded and therefore cost less to run than using 95 Ron.
Could have been that engine configuration that gave good results(?) Maybe the benefits are less in a more up to date engine(?)

It actually seems to be improving as the engine frees up, in spite of the heavier right foot

NorthernMogman, I think it's the other way round.

The more sophisticated the engine management system (e.g. air mass metering, fuel metering, direct injection, knock sensing, etc.), the more it is capable of extracting the best from the available fuel. Many of the new 'super fuels' also feature sophisticated detergents which keep the injectors clean and so maintain efficiency.

It's down to maths thereafter for extra m.p.g. vs cost at the pump... Though I doubt that Crocodile Dundee would bother to get his calculator out

...better ask Wal then..