Ok, Ive got a bit of a tricky question for anyone that knows carbs well. Im pretty sure everyone has heard the 200mpg carb stories so Ill sart off by saying this is nothing like that. But I was wondering If anyone has been able to tune or mod a stock or after market carb to get higher mpg. Like 10-15mpg higher then the norm on an older subaru. As well if it is possable is there loss in proformance or over all power. Just a silly thought but it would be great to beat out the price at the pumps and mabey run alittle cleaner at the same time.

To get 10-15 MPG better than what you have right now:

1. Convert to SPFI

2. Crank up the timing to 23-24 deg.

3. Install a cruise control

4. Drive at 55 mph.

5. Drive ONLY on the highway.

 

No magic carburettor, just good maintenance and driving very conservatively give the best results.

The only way you're going to get that much extra mileage out of a car is to only drive it downhill.

 

Seriously, the stoichiometric value for burning gasoline is approximately 14.7:1, which means it will burn completely at the point where you mix 14.7 parts air to 1 part gasoline. That ratio can't be changed, which is why the 200 MPG carbs are fairy tales. You can run a little leaner, but performance will suffer proportionally. Putting something like a Weber on your engine improves performance and mileage slightly, but only because it allows the engine to breathe a little more efficiently.

 

Given the basic layout of the Subaru, 30 MPG, which is what some people are claiming to get, is really good mileage. To do that, you have to drive very conservatively, which is the single biggest thing most people can do to improve their gas mileage.

Well I got about what I expected from that question. Just thought Id through the thought out and see what happend