Im suprised by your numbers bluedragon, my 97 mpi used to get only 35 mpg around town but I changed my habits and now I get 43-45 on my daily 20mile round trip commute according to my log book. If I jump on the highway it drops to 38 mpg for that tank of fuel. The other twin point car in our club gets 38 as well, but the motor has almost 3 times more miles and a performance head and roller rockers.

My 800+ mile trip from dallas to denver averaged a 34mpg with a low of 32mpg.

 Changing the final drive ratio from the 3.44 to a 2.95 or a 2.76 is a fantastic way to increase mpg. stick to the 10 or 12" wheels keep them narrow and inside the fenders with little to none arch. 

I would think that a proper airdam would improve MPG.  I will say that I noticed a drastic effect to top speed availablility by adding an airdam.  It improved my top-end speed easily by at least 10 mph on my 1275, and it made it so much easier to keep at 70 mph.

Quack.  Quack.   Orange Cream soda.  Shaken, not stirred.
Served with a side of melted peanut butter toast.

On the highway, your crusing speed can make a big difference. 70 mph vs. 60 mph can mean a difference of up to 4 mpg. This is due to the very poor coefficient of drag on the Mini.

I have some figures for the last of the Minis in 97. The standard model's cD was .49 - the Sportspack was .54! A modern car will be between .32 and .38, maybe higher if they are building a car for downforce. But I don't think we have much in the way of ground effects on our Minis.

I have an MPI and it has never come close to 40mpg. I carefully measure my fuel intake and record mileage on a spreadsheet, and have checked my speedo readings (on most Minis, 10-15% high.) Best single shot I ever had was 35 mpg. Avg. is 30 mpg over 105 refills. City commuting mileage was better than open highway mileage (27mpg on Interstate cruising from Seattle to Montana.) Engine appears to be tuned correctly according to exhaust gas analyzer on the dyno.

I'll bet 10" wheels, 145 or 155 width tires, and a minimum of arching for the wheels would help (by reducing drag and unsprung weight.) The 13" increase drag a lot as I've noted, and heavy wheel/tire combos take more power to spin up.

 

 

DLY

Actual comparison of our carbed 998 and MG Metro 1275 on return trip to MMW '97 in Vallejo (OK, it's bankrupt now, Vallejo that is...).  Both consumed the same amount of fuel and got +40mpg.  I'm getting slightly better mileage (+41mpg) on trips than either of those with the 1380 running through 2.95:1FD while pulling the trailer (add +400 lbs. too).

SPI and MPI would do better mileage wise I'm guessing.

David Vizard has some very useful advice to offer on economy for carbed cars and did the 55mph/55mpg drive around the US.

Mini friends!  Mini rides!

Restored/modified Mini 1000 with 1380cc power unit, 2.95:1 FD, adj. suspension, S discs/drums, 10x5 Minilites, 165x70 A008s, custom trim and matching custom trailer.

ride your bicycle while building up a 1275cc mini engine, using advice gained via the internet.

You will not have to worry about fuel for a long time.

Or leave the 850/998 in the car, sort it out, change your driving habits, most notably the choice of when to not drive.

I'm sure a lot of people will have allot of good input on this. But ultimately what do you consider to be good gas mileage. 

I would go with the 1000cc over the 850.  I my self went from an 850 up to a 1275.  I was able to get 40+ mpg on the 850.  When I to the 1275 I went down to about 20mpg.  The reason I went down so much is the 1275 is 425cc over the 850, there for burning 25% more fuel at speed, that and how can you not jab a 1275 in the ribs a few times going to the supermarket?

The reason I would say the 1000c over the 850:Both of these motors will get roughly the same gas mileage.  The 850 will have to work harder to get you going burning more gas through acceleration and the 1000 will burn more gas at running speed. So ultimately it depends on the Brick size of your shoe. 

Even if you go with the 1275 you can tickle 30+ mpg.  This is all about driving style.  Driving style will ultimately get the best mpg.  Just by looking up the road and seeing a yellow light and coasting to it will save you considerable mpg.

The above is considering you have your services covered.  Clean air filter, newer oil, correct tire pressure and so on.

(Insert snide comment here)    

MPG is proportional to the way you drive so I would suggest you look at your driving habbits and see where you can reduce your fuel useage. There are gadgets you can buy that tell you if you are driving efficiently or not. The best mechanical way to increase the mpg is to take it to a tuning place and have the timing with the 123 dizzy and the carb mixture optimized.

I was wondering if anyone out there has set out on getting the best mileage out of a Mini?  With these gas prices, I want to up my car's efficiency.

I have a 1963 rolling shell, it had the 850cc, I also have  a 1000cc out of a '65 that was getting 42 before I got rear-ended, and lastly, I have a 1275 from a Austin America.

I figured on running a header for better breathing, I also have a new 1-2-3 distributor if you think that would help.

Any other ideas? Carbs, filters, synthetic oil?  I  would appreciate any input on this.

Thanks a bunch, guys!