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Old 09-11-2016, 11:42 PM   #27 (permalink)
Experienced UAW Mechanic
Join Date: Sep 2014
Location: Bear Lake
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Originally Posted by darcane View Post
At 285hp for the 4.8L vs 295hp for the 5.3L, I was fine with the smaller engine. They are pretty close in performance, with a slight edge in power for the 5.3 and economy for the 4.8. In spite of the high gears, it tows our 4500+ lb travel trailer
The 3.23s are too tall for best mpg, but they do let you shift to a lower gear at higher speeds, which can help highway towing.
When it was new, and came with 3.42s standard, GM called the 4.8 " a real sweetheart " in regard to fuel efficiency, ( stock ). Back then the standard tires were 235/75R16, which was unusual. I drove a U-haul one and was impressed, it pulled away from a Vortec 5.7L C1500.
That's part of why i have bought 2 of those engines since. That, and they can be turbocharged past 1200 horses with just porting, a cam, valvesprings, ring gapping, injectors, fuel pump, and a tune. Doesn't even need forged pistons. I still have one, not turbo'ed yet.
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