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.

 

[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.