700r to sm465 swap mpg major drop

[82355]

I'll reiterate, my 1988 V10 Suburban saw no really noticeable difference in fuel economy when going from a TH700R4 to an SM465.

Martin

 

[Metrodps]

Pfft keep the 700r4 the DP burb was a four speed and the best I could do was 13 with the stick on highway it has 3:73 axles and it screamed at 65mph.

 

[Metrodps]

BTW I was running synthetic fluids in it too. Are you winding out the shift points? I drove like an old fart too.

 

[Metrodps]

OK re reading the whole thread again I have to ask do you have the auto hubs or manual? I pulled the auto hubs first thing and ran the manual ones in free. Just throwing things out there. I just gave my tilt stick column to a member last month.

 

[MechroMenace]

alright so I've come to the conclusion on what was killing my gas millage. the fact that I never had more than a mile to drive to get anywhere in town and Im not a very efficient driver when it comes to manuals. I drove 600 miles from idaho to southern utah and got 12mpg at 65-70mph ish the entire way. I also had it full from the front seat to the barn doors so I feel pretty good about it other than the 350 felt gutless as my sisters civic going up hills even with it at 3000rpms it would lose speed going up a hill. it may be a little tired or the suburban needs to go on a diet or both.

 

[diesel4me]

A Burb weighs roughly 5000-6500 lbs depending on what model and axles,and other drive train parts it has..stuffing it full from the front seats to the barn doors,add another ton ,maybe more...a 350 is only so strong even in perfect condition..
I'd say it did pretty good under those conditions..