so, I have a 2000 chevy express Quigley (4x4) van with a 454 in it. Im tired of getting 8-11 mpg in it as I plan on traveling quite a bit in the next few years. will a turbo or twin turbos with a tune help in mpg? this van weighs 7000lbs empty and on our trip to Cali it weighed 9500lbs!

 

turbos only generate boost dependent on engine load. more engine load=more duration in boost= more fuel you will use. high grade octane fuel will need to be used so fuel cost will also rise.

a 454 is a massive engine. there is no way around its horrible fuel consumption. 8-11 mpg is pretty good for such a massive engine.

the only thing i can think of is a conversion.

you can convert it to a small block chevy and then turbo charge the small block. this will allow for better cruising(low load) fuel economy as boost is not needed but when a high load is needed you will have the extra power.

or

you can do a duramax diesel conversion. even better fuel economy but very expensive.

 

ive thought about the duramax but it's just too much money right now. was hoping a turbo would add some efficiency. thanx for the info.

 

A turbo isn't likely to add efficiency on its own, but a turbo on a smaller engine could potentially get better mileage with the same amount of power. Would swapping in a 4.8 LSx be an option?

I suspect you could gain more mpg from weight reduction and an aerodynamic cover over the top rack. Having the cargo just stacked up there is costing you a significant chunk of horsepower pushing it through the air. And recently I sold a set of '90 Suburban brake rotors to a recycler - they weight over 70 pounds! I've got to wonder if some aftermarket discs could shave a significant chunk off unsprung weight if it was running aluminum hubs and rear drums. Not sure if there's a source for such things though.

 

this pic is from our trip to Cali where it weighed in at 9500lbs.. it gets basically the same mileage either way...8-11 depending on the wind and what fuel I use. the further west the less ethanol in the fuel.

thanx for all the thoughts. I will look into changing some things. I just wish it had a diesel in it already. my next one will have one.

 

The only financially viable mod would be to change your diff ratio to a lower number....gear it up so that its only turning over at 1500 revs at hyway speeds ,(or fit a 2 speed diff) surely it would have the torque to do this! Maybe a propane conversion would be worth looking into as well.