convert all wheel drive to a 2 wheel dive

[john1962]

Is it possible to convert an all wheel drive suv { 98 olds bravada} into a 2 wheel drive to save gas. like maybe disconnecting one of the drive shafts.

[curtis73]

The easy answer is not really. The thing that is taking the most fuel is all the extra rotating mass of the front axles, center carrier, and driveshaft. AWD vehicles always have the front axle shafts engaged, so even if you removed the front driveshaft it won't change much. The only way to get 2wd mileage is to replace the whole front axle with a 2wd assembly, but I would guess that it would only get you 1-2 mpg at best.

A cheaper way to get 1-2 mpg is to run skinnier tires and give the guys at www.pcmforless.com a call to have your fuel curve retrimmed. The factory fuel curve is a little rich; both for NOx emissions and for detonation tolerance. You can pull a little fuel out and still be fine on 87 octane and pass emissions. I do it in CA, and if it passes here...

[INF3RN0666]

Just a question, wouldn't it be easier to convert it into front wheel drive just by removing the rear axel assembly? I'm sure that'll have very little effect on gas mileage though.

[curtis73]

Well, that brings up the rest of the story. The 447 transfer case you probably have in there is a 30/70 torque split. If you took the front driveshaft off, it would just slip the front only sending 70 of the torque to the rear. If you pulled the rear driveshaft, you'd only get 30% to the front. It can be done, but you'll need an actual 4x4 transfer case, or find a way to lock your transfer case to permanently tie the front and rear outputs together.

The "proper" way to do it is to go get the parts from a 2wd blazer and swap them over; transmission, rear driveshaft, complete front suspension including brakes, spindles, control arms, springs, hoses, etc. For that cost, though you could probably buy a 2wd blazer.