Changing the Gear Ratio

[Mat7103]

Could you change the RearEnd to somthing smaller

For better gas Milage?

If so I have a 85 Chevy 366 Big Block 5spd,

Not sure what the gear ratio is But i want it smaller for better Fuel Economy. What could i drop it to? If i Could.

[Steve]

You need to ask yourself if you engine has the excess power. Does your engine have more to give you than you are already getting?



Remember, just because an engine isn't turning as fast doesn't mean you aren't dumping just as much gas into it. With an object shaped like a brick going down the interstate you are always under constant acceleration.

[Mat7103]

I just want to thank you guys for all the help



i wondered what

can WE ALL do to help our Skoolies get better gas milage?

[Steve]

The thing that will increase your gas mileage the most is to drive slower. One of the things I learned in my fluid dynamics classes is that drag on an object such as a car increases exponentially with speed not linearly. So even slowing down just 5 mph will greatly reduce the drag force excerted on the front of you bus.

[caddywumpus]

I work at a trucking co and sometimes the drivers bring in these magazines from the truck stops most are free and are just trying to sell you their schwag. Anywho I noticed the other day one was selling these foam pieces that attach to the corners of the trailers. Wind foils for the bus. Makes me think if i do a conversion I guess I will need a big polished aluminum chicken wing like the rednecks have on their peterbilts. I think that would look cool on the Black Plague...flames crome stacks and big ole chickin wing on top.

oh yeah momma sita! 8)

[lapeer20m]

another big factor is cost. i've heard anywhere from 800 -2000 bucks to change the ring/pinion.



That's more than most of us paid for the skoolie to begin with.



If you increase you top end speed, you most likely won't improve on fuel economy at all, but lets pretend we're in a perfect world for a few moments:



assuming you get 8.5 mpg now, and it was increased to an unlikely 12 mpg, you would save about 34 gallons every 1,000 miles. @ $1.50 per gallon of diesel, that's $50.00 in fuel savings/1,000 miles traveled.



if it cost $2,000 for the rear end swap, you'd have to travel 40,000 miles to make up the difference you'd save in fuel.



If you planned to keep your skoolie for a long period of time, perhaps the $2,000 would be worth it. The top end speed I think is more beneficial than the improved fuel economy.

[EldoMike]

Yeah, to me the biggest advantage to higher gearing is so you can get a little bit of a run at a hill....sucks when you can only do 55 when you hit the bottom of a mountain....



EldoMike