What is the fuel consumption difference between a 12a standard non turbo and a 13b standard non turbo motor ?

Is the power difference worth the fuel ?

 

That's kinda a loaded question. In the case of the GSL-SE motor, power was increased by 1/3 in both hp and tq over the 12A with only a couple of MPG drop in the EPA ratings. In the real world the difference is lessened because the 12A came with the Nikki and the later 13B motors were fuel injected. In the initial review of the GSL-SE, Car and Driver observed 22mpg. The way they trash their cars, that's pretty good.

 

I just recently managed 19.91 mpg on my 84SE with mixed city/highway driving, granted about 3/4 of this was highway driving with cruise control set for periods of about 30-45 minutes each.

That's about the best mileage that I've gotten in several months. I usually average about 15-16 mpg for mostly city driving, which still isn't bad, since my Q45 gets about the same, if not worse.

I don't tend to drive too fast, I take off from lights shifting at about 4k, and hardly ever redline the engine. The more right foot you use, the less mpg you're going to end up with. Something to think about.

IMO, it's worth it.