Boring mpg question - classic mini 998cc

[JIM600]

I know PH isn't really the site for economy matters type questions

But we are planning to use a 998cc mini engine in a spaceframe chassis (ie no bodywork bar mudguards) for a trip to Morocco/North africa (although it's one of many vehicles currently in the mix).

We really need close to 50mpg from this car (pair of motorbikes are the alternative option which will happily get 70mpg).

It ll be a very low mileage, manual 998 engine in a car weighing about 500kg and with no bodywork. And lets work on the basis that everything engine wise is setup for mpg over performance.

Is anywhere near 50mpg going to be possible - Ive heard of low/mid 40's on standard minis driven day to day. Hoping 50mpg could be done with the lighter frame/car

It's not the biggest concern but would go along way towards justifying the mini engine over the motorbikes.

Thanks

[guru_1071]

with a tall diff it would be posible with ease


vizard got some impressive mpg when he drove round the states in that yellow clubman

[annodomini2]

Bodywork would help with mpg, at motorway cruise speeds Aerodynamic Drag and Rolling resistance are the biggest factors.

[JIM600]

annodomini2 said:

Bodywork would help with mpg, at motorway cruise speeds Aerodynamic Drag and Rolling resistance are the biggest factors.

Yep, that's one of the concerns, these frames are pretty un-aerodynamic, especially once loaded up with gear/spares. Sort of hoping that the weight savings will help equal out the lack of bodywork. Having said that - motorways are not something we will be aiming to use much anyway.

How about reliability, will a fresh built or very low mileage a-series engine have any weak spots over its first 15-20k miles? Aside from general maintenance?

thanks

[annodomini2]

JIM600 said:

annodomini2 said:

Bodywork would help with mpg, at motorway cruise speeds Aerodynamic Drag and Rolling resistance are the biggest factors.

Yep, that's one of the concerns, these frames are pretty un-aerodynamic, especially once loaded up with gear/spares. Sort of hoping that the weight savings will help equal out the lack of bodywork. Having said that - motorways are not something we will be aiming to use much anyway.

How about reliability, will a fresh built or very low mileage a-series engine have any weak spots over its first 15-20k miles? Aside from general maintenance?

thanks

Main issues are usually electrical on a well built/maintained engine.

There are usually 2 camps, points and electronic ignition, Electronic will tend to work for longer, but when it breaks, that's it the cars going nowhere.

With points there's a higher chance of problems, but they are less likely to leave you stranded.

Everyone has their own opinion on which is better.

[JIM600]

Ok, that's not too much of an issue - shouldn't be too difficult to carry a few electrical spares.

Is the 998 the best allrounder in terms of mpg/reliability? Or is there a better engine/a-series size that will fit the mini subframe - from what I've seen anything over the 998cc size a-series starts to be quicker but mpg suffers.