my car is starting to make weird sounds the engines going i know it, should i trade it in?
if so what older vehicles have awesome gas mileage, new cars ive always heard dont have the same gas mileage
but back to the point what car should i get

Depends on your budget and preferences.

2007 model Toyota Camries are pretty decent for fuel effiency.

Something with a diesel engine to make it run on bacon grease.

A friend of mine runs his diesel landcruiser on straight fish'n'chip oil.

Rather than just buy a new car, why not just take your current car to a mechanic and get the engine checked first?

it has less gas mileage, my datsun got like 40.

i have they said repairs would be pointless because the parts could buy me another car
its an old datsun
it was my first car, he told me to let it die, that was a year ago

http://usnews.rankingsandreviews.com/cars-trucks/MINI_Cooper/

not a big fan
but i do like the site!

Just bought an beat up old 1987 GMC Jimmy 2 Door (A Chevy Blazer) that I am in the process of getting legal. As it's the weekend I'll have to wait 'till Monday to make any headway. If you can stand getting a vehicle that's likely older than you you could go with 80s cars.

If you can find a mid 80s Honda Civic, Accord, or nearly anything other mid 80s Japanese car they're rather good on fuel and have been around long enough to be rather cheap. The only problem is finding one with a decent amount of miles on it. I have a personal like of late 80s Mazda pickups, myself, and they get around 30 MPG, as far as I know.