Chevy & GMC Vans

Is 20 mpg for a stro good for freeway driving? I drove from Portland to Seattle and then around a bit, for a total of 400 miles on 20 gallons of gas. I used cruise control as much as possible and stuck to the speed limit.

Yup, that is on the upper end of what an Astro or Safari will get.

LiftedAWDAstro wrote:Yup, that is on the upper end of what an Astro or Safari will get.

Cool...but...I want more...more...more power...more control....and a daily allowance of graham crackers for my snack break please

Doesn't sound too bad.

Of course you want more. You could try some underdrive pulleys. Slowing down the accessories puts less strain on the engine.

20 MPG is excellent. Remember, you're pushing a box through the air. At the cost of diesel fuel and the cost of a diesel conversion, it will be a very long time before you realize any savings. Then add the expense of a transmission swap. It sounds like you're backing up. If you just want to do a swap, then put a small block Chevy in it. And stick with the 4L60E. It's a proven setup.

Smiliesafari wrote:20 MPG is excellent. Remember, you're pushing a box through the air. At the cost of diesel fuel and the cost of a diesel conversion, it will be a very long time before you realize any savings. Then add the expense of a transmission swap. It sounds like you're backing up. If you just want to do a swap, then put a small block Chevy in it. And stick with the 4L60E. It's a proven setup.

If I go for the V8 swap should I find a V8 version of a 4L60E? Things seem to be doing OK for now but I want to try to be a little proactive with this. Come June of next year I will be on the road a lot during the weekends so I am hoping to take a close look at all parts of Jane and see what, if anything, should be addressed first. I also want to pick up a trailer, which is why I am focusing on the tranny.

If that transmission is the original (200,000 miles) it's due for a rebuild. There are some upgrades that should be done at the same time. Bill (lockdoc) is better versed on that subject than I. Maybe he'll add his expertise.