Thor Forums

[gmtech16450yz]

Originally Posted by Rocky49

Welcome to the Forum!!

Nice to hear someone with GM experiences on the Forum. Don't have a vegas but a Thor Class C with the GM V8 powerplant drive train. I have been a ford guy, a Volvo guy, a VW guy and now a GM guy. I would love someone who could tell me how to improve the fuel economy in my Class C Thor, besides going slower and travelling empty. My local Chevy dealer says it is a cube van, no one cares about cube van efficiency!!!

What you are describing with your Thor is what many people have experienced a decent overall design, but poorly finished or completed, and a lot of folks who just don't care because they are making money NOW! It is kind of like the US auto industry in 1971. And as you correctly point out many of our RVs cost less than a new Caddy or Lincoln. We would like more quality but can we afford it. Sometimes I think it just comes down to getting folks to do the job right the first time.

Rocky 2014 GM powered Thor Freedom Elite 23U

Is yours an L96 or LC8? Doesn't really matter actually, they both have VVT and knock sensors. Both of those help mileage and a good tuner can eek a little more out of them. If you want more power, there are decent gains to be made with ignition and cam timing on those engines. You'd have to run premium to get that power though. (Most) any engine with knock detection will make more power on premium fuel, especially GM engines. GM runs their ignition timing VERY aggressive, and uses the knock sensors to retard it to suit the fuel you're using. Running premium will keep the ignition timing from retarding, which absolutely results in more power and better mileage. Is it enough to make it worth while? It depends on the engine and tune. On some, like late model GM trucks and SUV's, running premium will gain you enough better mileage to offset the price of the premium fuel. So you basically get free horsepower.

On your particular engine on STOCK tuning, I'd run premium fuel if you're towing or driving in hot, low altitude situations. Cold weather or high altitude driving should be ok with regular 87 fuel.