my engine is pretty old and very poor on gas mileage, i cant even get 300 miles on one gallon of city driving, and therefore, i want to rebuild or replace my engine with a remanufactured one, but i dont know which is better...
i dont want to swap in another engine like a h22 or something because i think the f22 in my car is just fine, and with the route im going, the engine will run almost like new
so what should i do?

 

If you can get 300 miles on one gallon, don't touch anything...

Rebuild vs. replace is sort of an economic question. Depends on the labor rate for who's going to do the work, vs. the cost of a reman engine. If you do the work yourself, decide if the hobby value is worth the time it would take. Because if you're not in the business of rebuilding engines, it'll probably take enough time that you won't want to calculate the $ per hour rate that results.

 

1st I would do a compression test to see if you actually need to replace, if the compression is good I would look into getting the egr ports cleaned, the fuel injection serviced, with a new fuel filter. As you can see I have a 92 with over 390,000 miles and the compression is 150 psi per cylinder, I get 27.5 mpg. Don't replace unless there is a actual engine problem.

 

if I was a mechanic I would say come on over and I will hook you up with a new engine.......

typical causes of poor milage

bad O2 sensor
clogged EGR
brake drag
underinflates tires
stick open tstat

 

As everyone has stated make sure that your car needs it first (compression check), if it does and a shop does the check ask them which way is going to be cheaper. If you're going to rebuild you may consider doing some engine upgrades as well...

 

im thinking that rebuilding will be cheaper, because i looked into some engines for my car that are remanufactured and they cost around 2.5k, then labor
but to get the parts to rebuild; titanium retainers, new pistons, piston rings, bronze valve guides and stuff, it would be like around 1.5k, plus labor and port polishing and all that good stuff
my mechanic is a good friend too, so i think i might be able to get it cheaper on that part

how many psi per cylinder am i supposed to be getting?