Engine upgrade MPG averages?

[Timebender]

This is to that subset of owners who have opted to convert their beloved DeLoreans to a more powerful power plant- namely a Chevy Small Block - whether that’s an LT or LS.

The question is, what kind of gas mileage have you been getting on average with this setup?

I ask as I currently have a late 70’s SBC 350 out of a Corvette, performed by the original owner, and it’s close to time for an upgrade/replacement.

Btw- on average with carb, I’m getting anywhere from 19mpg to 15 (why the drop I have no idea, as I do a lot of freeways at about 65-70 mph).

[Nicholas R]

Before the cam and head swap (stock LS1), I got around 24mpg highway and 18mpg around town. After the cam and head swap, I now get around 21mpg highway and 15mpg around town. It was a price to pay for the extra 100+ hp but it's worth it to me. Part of the problem to is that, when the power is there, you want to use it, (especially because the setup adds a lot of power in the early/middle of the power band). I'm sure I could coerce the MPG back up to the high teens if I had no fun in the car, but then.... where' the fun?

[Timebender]

I find if I keep my foot pretty much off the pedal and at a cruising speed of 65 (the actual speed limit on most freeways here, though some spots are 70), I can maybe get close to 19 average. But then there's the every so often I have to get around a semi, or some guy in his Mustang or Camaro will slow down, do a couple revs to challenge me, and I have to put them in their place... or at least show them the DeLorean just doesn't look fast.

The only problem with that is my daily commute is 100 miles round trip - so I have to get gas - currently at $3.75 a gallon for 91, every other day.

So it would be nice when I get a new engine to have both power and some economy.

I've even been considering putting in a Chevy V6 - if that will bolt up directly to where the 350 is now.