2000 montero plans concerns and problem

[philjherman]

Decisions decisions. I am still torn between 32 and 33s... I wish 32s came in a skinny version. I'll rattle this around in my head a bit. Thanks everyone for the info. Maybe 33s will come a few years down the road.

 

[RttH]

Thanks roger I am in arizona, a bit lower but rocky too. I would probably have to regear at 33s. I think for now I will look into 32 or even 31 inch tires. Did you regear when you got the 33s or when you had 32s?

Stioc I always forget about metric tires I will look into them but I do want to keep the stock rims.

I really do like what I hear about ome suspension. Does anyone know if stock torsion bars at 97000 miles should be replaced before lifting them an inch and a half?

I re-geared after I got the 33's. It was during an offroad trip above Breckenridge, CO that I noticed I needed to re-gear. On a very steep decent my gearing wouldn't slow me down enough and on climbs I could smell the tranny getting hot. Since then I have had no problems. On highway the lack of "oomph" keeps me from getting speeding tickets! But seriously I don't notice it so much on highway, even loaded with gear.

 

[off-roader]

I re-geared after I got the 33's. It was during an offroad trip above Breckenridge, CO that I noticed I needed to re-gear. On a very steep decent my gearing wouldn't slow me down enough and on climbs I could smell the tranny getting hot. Since then I have had no problems. On highway the lack of "oomph" keeps me from getting speeding tickets! But seriously I don't notice it so much on highway, even loaded with gear.

Well Breckenridge is 10k ft above tuscon but you bring up a good point for the OP. What altitude will your trips be at? At higher altitudes, the impact may be greater.

As for the tranny getting hot, yup, it can and does happen off road. It's a good idea to regularly flush your transmission. You should also consider removing your transmission oil pan to inspect the wire mesh filter.

If the tranny does get hot, you just need to pull over and let it idle for 15 minutes or so. The transmission gets hot when it works hard such as driving uphill or if when trying to slow your vehicle going downhill. It also raises the temps if your cooling system isn't up to par.

 

[off-roader]

Decisions decisions. I am still torn between 32 and 33s... I wish 32s came in a skinny version. I'll rattle this around in my head a bit. Thanks everyone for the info. Maybe 33s will come a few years down the road.

Perhap's there's a skinny metric equivalent?

Personally though I prefer fatter tires for the added protection off road. If anything, I'd only use skinny tires for daily driver use or if I was always in specific situations where they'd help.

 

[shov3lbum]

I love my 33 x 10.5 x 15s on my montero sport. I have a manual transmission so heating up isn't as much of a concern off road, and my gears are 4.66 already! As for loss of acceleration, some, but I just hold my gear shifts longer and regularly go up to 5K rpm in first and then cruise at about 3k rpm at 70 mph or so. I pulled a 12x6 dual axle uhaul trailer fully loaded (3k ish lbs) with this setup, keeping above 65 mph was a challenge especially encountering highway hills and that was at my current elevation here in flat wisconsin.

I think for the clearance you gain, the little bit of power loss is worth it. As others have mentioned protecting that pumpkin is key. I'll see how bad the power loss is this summer when I'm in Colorado on the trails. I imagine I will be spending a lot of time in 4th gear to maintain speed no doubt. Also your speedo will be off (read lower than your going) by about 4-5 mph at 65 mph. My gps is permanently mounted in the rig for this reason alone. :sombrero:

 

[RttH]

I also use my GPS to monitor my speed. My speedometer is off by almost 7 mph! :Wow1:

 

[off-roader]

I also use my GPS to monitor my speed. My speedometer is off by almost 7 mph! :Wow1:

At what speed? It's all relative.

Mine reads ~10% slower with 33's (50mph when I'm actually doing 55mph) and closer to 15% slower with my 35's.

 

[RttH]

Anything above 45 and I really notice the discrepancy. 50 on the speedo is about 57 on the gps. 65 = about 74 on gps.

 

[off-roader]

Roger what size tires are you running?

 

[RttH]

33 x 10.5 x 15 BFG KM2 I really like how they feel compared to 32 x 11.5. They feel more responsive and when I air down I get a much better contact patch than a wider tire.

 

[shov3lbum]

At what speed? It's all relative.

Mine reads ~10% slower with 33's (50mph when I'm actually doing 55mph) and closer to 15% slower with my 35's.

Mine is off by about 9% slower

 

[RttH]

I checked it again this am on the way to work. I may have misspoke...at 40 my gps read 45, at 50 gps read 55. I do know that at higher speeds like 75 I am off by about 7 mph. My 33's have almost 30,000 miles on them now so they may be a bit smaller than 33.

 

[off-roader]

...and when I air down I get a much better contact patch than a wider tire.

Can you define what you mean by better?

A wider tire will have a larger contact patch and lower weight per square inch.

A narrower tire will have a smaller contact patch and higher weight per square inch.

On pavement, the 2nd is better for maintaining traction especially for slipery conditions.

Off road, the first is better in most situations except in conditions like shallow mud where you want the tires to dig in and get to the bottom of the mud hole where there's solid ground. For deep mud, or sand, wider tires with a bigger contact patch is almost universally preferred.

On second thought I just read this http://www.expeditionswest.com/research/white_papers/tire_selection_rev1.html...

 

[RttH]

You are correct in that a wider tire will have less pressure when aired down which is good for sand, etc... Here is a great paper on the subject.
http://www.expeditionswest.com/research/white_papers/tire_selection_rev1.html