I have a 01 rodeo and I get about 19-21 mpg mix driving, that is after I change my spark plugs. Before I was getting 17-18.

From what I have been told if the timing belt brakes your engine will be fine

You need to take care of the transmission. I just got mine replace. Check and change the fluid and don't dive crazy and you should be fine. Also there is no dip stick so you have to go under and check it.

I have not had any electrical problems, so I can't really help you there

A lot of Isuzu like to eat oil. I have been try to cut that down by using sea foam. Put it in your oil and let it run for 15 min. right before you change you oil. I have cut it down from a quart every 600 miles to a quart every 1200. Also I was told to use Shell Rotella 5w-40, it has work vary well so far and it helps clean.

I hope that helps a little, I am still learning stuff.

-Mr. Jeff
2001 Isuzu Rodeo
97,000, 4WD Automatic, LSD