I faithfully record every mile, .1 gallon of gas and quart of oil I put in the GMC, just like with the CRV. I don't think I've EVER calculated the MPG. I know I haven't since installing the 500 Cad engine. Why would I?
I'm not likely to follow Jim H's recommendations to gain a couple of MPG.
That's sort of like the Lexus. It's the only car I've owned in the past 70 years without a mileage log -- why bother -- if I'm gonna drive it, why sweat MPG?

JWID,

Ken H.