Which is better on gas, horsepower, and reliability, the 5.7 or the 5.3?

 

Both are about the same as far as gas mileage goes. The 5.7 has more torque and horsepower from just the size. Both are very reliable engines.

 

I have 3 trucks with 5.7 motors all 3 are 3500 dually work trucks mpg varies from 8 to 12 mpg I would say and the power is fine for a smaller work truck. I bought a 2007 siverado with the 5.3 and would say it has similar hp ( I know the 5.3 puts out 315 hp) but the gas milage is better at 16 to 17 in the city? I like the 5.3 much better!

 

I have had each of these and i feel that the 5.7 has good power with the 5.3 not much behind. id say either one is a toss up for towing as long as you go with the 4.10's. As for racing, my buddie has an 05 with a hypertech only and my 98 5.7 leaves him in the dust with no mods. my truck might have something done to its computer, because ive never lost to any other 5.7's though