Recently purchased a 78 Austin Mini 1000 and the odometer does not work. Wouls like t know what mileage to expect.

Around 40 MPG-on flat roads.....!

Maybe 40 on a good day, downhill. It really, really depends on what's been done to/with your car and engine.

My 1275 -S gets about 22 MPG around town and since the aerodynamics are awful, maybe 25-28 MPG at about 60 MPH. The 998 engine will be more economical but again, any "go fast" parts added to your engine will likely lower the fuel economy.

When I see people quote 40 MPG and higher for a Mini, they are often in the U.K. The Imperial gallon is bigger than the U.S. gallon. Reduce U.K. MPG figures by 20% and you're close to the corresponding U.S. value. (i.e. 40 MPG U.K. = 32 MPG U.S. )

Doug-I was assuming a stock and healthy one carb engine. I have a later 1275 single carb and I will get 35+ mpg at 70+mph all day long-but then again, I have a nice low gear in my final drive. I drove it every day for almost two years commuting to work doing 250 miles every day. I am building an econo 850 Mini for daily driving and I am looking forward to some great MPG numbers from that Mini.

True, I hadn't even considered the final drive aspect. My car is running dual HS2s, 10" tires, and the 3.44 final drive. That equates to 4000 RPM at highway speeds. That doesn't equate to economy the way a 3.1 or lower final drive would.

Keep us posted on your economy build. Steve Gibbs in VA has done similar builds with economy final drives on 998 engines. I've always been envious of his fuel economy.

When changing gear ratios, be certain to factor your registered miles, or use the easy way, a GPS.

Mileage will vary depending on how "Spirited" you drive your Mini. I can't keep my foot out of it so my mileage suffers. However my grin gets bigger as I zip round corners as fast as possible.