How slow is too slow ?

[MisterBishi]

Hey all ,

I've got a '91 LWB v6 auto with about 190k on it. It runs smooth, gets from 20mpg in easy conditions in the summer to 15 mpg towing a snowmobile trailer in the winter. Running 30 x 9.5 General at2's so a tiny bit larger than stock.

We live in SW Montana in one of the windiest places in the U.S. . The truck does ok generally but even on the flats I have to lock out overdrive if it's windy (almost always and regularly 40 mph +).
Also need to lock out OD on any significant climb (multiple times on any drive around here). Towing even a single sled on the trailer is a struggle with second gear being used on many passes and basically locking out OD even on the flats. Does this all seem reasonable or is this old girl just tired ? Compression checked out around 135psi give or take 5psi for all 6 cyl. Not a smoker and the usual tune up suspects taken care of.

I also have a '89 SWB V6 manual that was a bit better but I'm thinking it was the 5 speed that helped it along with being 400 lbs lighter. I posted my cracked head dilemma about that one a while back and will update when I get going on it.

Thanks,

Dan

 

[cornfarmer]

My daily driver is a '90 LWB V6 auto too. 227k miles. Engine rebuilt about 10-12k ago. I live in the mountains and either disengage OD or I just engage the kickdown to get up some hills, so I'd say it's normal. It's a low HP, low stress engine but has decent torque, so for me it's a trade-off.

By comparison, I used to drive a much newer 4 cyl. Ford Ranger with the same HP rating. The Montero seems to have more low-end torque.

 

[PirateMcGee]

I grew up in Great Falls... Sounds normal to me, stock sized tires might help.

 

[kevinreeves116]

I live in Hamilton MT, not near as windy as where you are but am surrounded in hills. My daily commute to the gym and school has one fair sized hill in it. I usually approach the hill at 40mph in OD, once half way up I am slowed to about 38mph, then it takes it out of OD and then I'm back up to a desired 40. My rig has the auto as well but is riding on 32x11.5 mud tires. Its no corvette thats for sure. I mean c'mon, these things have the aerodynamics of cinder block! haha not fast machines at all. I'm thinking of upgrading the stock 3.0 to a Chevy 4.3 for college due to how slow it is.

 

[Hnoroian]

Good psi from all cylinders in match, but I bet the torque converter is starting to slip.

 

[Senor Carey]

Mine never got close to 20 MPG. One of the reasons that I didn't like driving it up the hill to the high country is that I felt it was underpowered. Would've been a great truck with 100 more HP.