MPG experiment....1976 Dart Lite

Just a few points to make sure you get an accurate base. In the process of doing the same thing to a standard Dart.

I would verify what gear is in the rear now, tyre size and make sure your speedo gear is the correct one. No sense in jumping through hoops trying to get mpg maxed when your numbers are skewed by being off.

There is a lot of discussion (sorry to talk about another board) about this same subject on the slant board where I have picked many a brain and read through posts for hours. Some great info!

First thing I'd do is get that carb repaired. You may just flat have a dud. Some quickie obvious things, but if the choke is not working correctly and not openning right then you are going to use more fuel. Parts missing? Wrong carb for car? What kind is it?

Does the car have any vacuum leaks?

Plugs and gap used?

Timing currently?

What rpm at 55?

Vacuum readings?

Total timing at 55?

Tyre pressure?

What do plugs indicate mix wise?

There are some starters.

Exhaust wise, seems the most popular upgrade if not going to DDuals or a header is to use a 2.25 pipe back from the exhaust to the muffler. A good quality muffler and then out the back with a 2" or stock 1 7/8". Very popular upgrade to standard exhaust and what I'm about to do.

Gearing wise that is up to you. Sounds counter productive to the goal of MPG as the turbo and increased gear sound more directed to performance and power. Granted, you can get those and still keep mileage, but depends what you really want out of the car. The 4 OD will help keep that under control though rpm wise while cruising I guess.

The car I picked up was probably getting 7 or 8 mpg for the previous owner. Bad state of tune, neglect, carb in poor shape and smoking fuel out the back etc. Basically did what you did above and rebuilt the carb and the car got 11 mpg. Started playing with timing, did the HEI and tuned the carb (1bbl Holley) and in general around town driving got 16.9mpg. Now have the pieces to recurve the dizzy, etc. so that is next as I've mapped out my advance curves and they are not the greatest in the world. Should get that fixed next week.

Oh, numbers are at just under 6000 feet elevation, 225, 904 auto, corrected speedo, 3.21 gearing and 225/60/14 tyres with PS & air (not running air during mpg tests).

Best of luck with it and perhaps see you on the slant board also.

Cheers