Carb to EFI

[bobcowan]

Assuming that both EFI and carb are properly tuned, you do tend to get better gas mileage, simply because the EFI is more accurate at part throttle cruising. I routinely get 18-20mpg.

More power? Peak power will be about the same. As long as you're comparing apples to apples, the peak power will be so close to the same that it won;t be worth talking about. But you'll get more power under the curve. Again, simply because the EFI is more accurate there.

IMO, the big advantage is drivability. On single day, I might see temps range from 70's to 30's, and altitudes range from 5,000-11,000' ASL. Some times I'll drive as high as 14,000' ASL. Last time I did that, the temp was 28*. With closed loop operation, the computer constantly adjust the fuel feed for the available air. When we were ready to leave, I just turned the key and drove away. Some of the carbed cars had a little trouble getting going.

And that's where EFI really shines, IMO. It compensates for weather and altitudes really well. A well tuned carb just can't do that.

Another bonus is it's ability to compensate for radical engines. If you install a radical cam, the engine typically doesn't like to idle well, or run well on light throttle cruise. Even with the biggest cam in the CC catalog, my engines idles nicely at 800rpm's, and will cruise all day long at 2,000. With port injection, you don't have to worry about maintaining intake charge velocity, or keeping fuel in suspension.

Another bonus is the ability to switch between pump gas and E85. I went to Moab a few years ago. It was really hot. Like, Africa hot. And, of course, we're all stuck in traffic at the construction zones south of town. Not a problem for me. Engine runs really well and cool with E85. There's a cruise event in Aurora every year. If it's a hot day, I'll run e85. Even in stop and go traffic, it never gets hot. E85 smells good, too.

The down side to EFI is, of course, cost and complexity.