285's and Mountain Passes...

[PACNW96]

I have been researching tires on MUD ever since I got my 80 back in 2004 waiting for the current 275/70's to wear out. I have researched the 265 vs 285 threads to death, but until I actually drive with larger tires I will never know. I am hoping to get swayed one way or the other by this thread and apologize for any repeat information as I know this topic is covered frequently.

My rig is primarily used for family trips across Washington in the winter where we will cross a mountain pass (4k max elevation) and go through the Columbia River gorge which is a fairly steep grade, but all relatively low in elevation compared to the Colorado passes. We don't tow anything during these trips.

I want 285's for a little extra lift during winter logging road excursions, but don't want to hit 2nd gear repeatedly when crossing WA mountain passes with the family. If I go with 285's I plan to install Slee's speedo correction gear as well to help with the shift points. If 2nd gear is my fate with 285's then I will most likely go the 265 route instead. I have no plans to regear for 285's.

I get nervous when I read threads like:

I drove the 80 from southern Idaho last weekend, and had to hit 2nd gear several times that I don't usually have to with the 265s, white bird hill and the lewiston grade. Granted, I had 7 people in there with some gear as well, but still....

What also concerns me there are muliptle threads where someone was trying to make the same decision, got 265's and now wish they had gone with 285's. Examples:

After reading all the tire threads I decided to go with Revo's. But I let the tire guy talk me out of the bigger size. 'Louder, rougher ride, odometer is off...blah blah blah...wife won't like 'em, blah blah blah.'

I gave in and got the smaller 265's. I wish now that I hadn't.

Yes I am running 265/75 sized tires! And Yes I do regret it! I should of went with 285/75/16.

Ashooter,

That is a tall skinny tire, are you unhappy witht he 265-75-16 you have on now or is this just due to needing replacements? I have the same size and kind of wish I had gone to the 285 series, especially since I am looking to gain about 2" when I replace the sagging springs.

Glen

I am really torn between the 2 sizes and can’t seem to be swung one way or the other. Any help would be much appreciated.

BTW...currently, running OME 861/862 low height springs with no plans for more lift.

Thanks,

Russell

 

[Devil's Slide Doug]

I live at sea level in CA and recently upgraded to 285 Cooper stt's. I was concernedd with the gearing which was a factor in choosing this size rather than 315's (along with the need to stow a spare in the stock location and only having an ome medium lift to clear the tires.

I have driven around town and towed a 3k tent trailer up to tahoe and such and my driving impression was "wow, this truck does well with this gearing/ tire combo, I kinda wish I had gone with 315's".
IMO the cruiser will easily handle 285 tires, even towing a moderate load. The 285 barely fits in the spare location and with stock bumpstops will rub the inner fender when flexed enough . I even managed to rub the inner rear slightly at highway speed in a big dip/turn while towing. Nothing to worry about.

 

[Tennessee80]

No worries, I think. I have had 285's for 1 year, as the PO had them on when I purchased the truck. I tow a 5,000 lb. catering trailer, and it downshifts quite a bit with that on the back, but hell.... I think youre fine, and the extra clearance will help on your logging trips.

Cheers,

Joel

 

[Fly Rod]

Don't worry about it. I have had 285's on the truck for a couple of years now. I am over Siskiyou Pass regularly. I also drive stuff considerably steeper on a regular basis. The only time I have hit 2nd was during a recent trip to Park City trying to climb a very steep grade fully loaded and staying in the fast lane. I only used second for @ 1 mile out of 1,600 miles. No big deal by any means.

The stock gearing does well with 285's IMHO.

 

[Nay]

The 80 is an underpowered pig to begin with. All you are doing is adding a little bit of bacon

I actually prefer 35's over 33's on stock gears, because OD Off is a better RPM match, and I never thought one bogged down worse than the other (they both did in the same spots). Keep the PWR button on over the higher passes, it makes a huge difference.

Get the LT MAF mod - by far the easiest way to compensate. Go 285's.

 

[tblume]

I'm running 305/70 = about 32.8 inch per a couple calculators online; Tire size calculator

stock gears, speed limit or less- (60-65 on the interstate, per GPS, shows 61 when running 65) a bit over on secondary roads, but the engine sounds like it's running great-not lugging or hunting for gears. I drop out the OD on hills before I hit 'em, and I got 209(per GPS) miles and show a bit under half tank remain, will top off tonight and calculate, but I think 285/75 is about the same diameter- around 33" and a bit more skinny, so a good AT at the top of the psi range should give fair mileage.

 

[mainemike]

No complaints with my 285s.

 

[Brian894X4]

I've run the 285/stock gear combination for a while now and I have no complaints. I don't feel like I'm underpowered at all and my rig weighes 6300lbs. That doesn't mean I wouldn't mind a supercharger or anything, but it feels just fine to me for normal driving. I have plenty of power left for passing and going up hills is no problem.

Then again, I know what underpowered is like with my 5300lb, 22RE truck with 35s and 5.29s.

I'm convinced the taller tires help with the gas mileage, as well, as long as you keep the speeds reasonable.

If I had to do it over again, the only thing I'd consider doing differently is maybe an even narrower tire, but that's just because I want to squeeze better mileage. Otherwise the 285 is the perfect size tire for a moderately built 80, IMO.

 

[PACNW96]

Thanks for all the positive responses. It is sounding more and more like I am making a big deal out of not so much as many of you are very happy with the performance you are getting out of 285's and stock gears.

I am a little gun shy as I made the mistake back in my college days of buying a Bronco with 33's and vividly remember shifting it into 1st to make it up a steep grade once and never forgot it. I was barely passing semi's at this rate.

Obviously my 80 is night and day difference and have had Toyotas ever since, but just want to make the right decision.

 

[Brian894X4]

One of the differences is that the 1FZ is a fairly high torque at low rpm engine. 4.10 gears are actually fairly low to begin with, especially with the torque of this engine. And the difference between the stock tires, which are just a hair more than 31" and the 33s is only a little more than 6%. Not a huge difference.

You'll notice some loss. There's no way around it, but it will be pretty minimal.

 

[Devil's Slide Doug]

I live at sea level in CA and recently upgraded to 285 Cooper stt's. I was concernedd with the gearing which was a factor in choosing this size rather than 315's (along with the need to stow a spare in the stock location and only having an ome medium lift to clear the tires.

I have driven around town and towed a 3k tent trailer up to tahoe and such and my driving impression was "wow, this truck does well with this gearing/ tire combo, I kinda wish I had gone with 315's".
IMO the cruiser will easily handle 285 tires, even towing a moderate load. The 285 barely fits in the spare location and with stock bumpstops will rub the inner fender when flexed enough . I even managed to rub the inner rear slightly at highway speed in a big dip/turn while towing. Nothing to worry about.

I did forget to say that I am accustomed to driving a 22re mini truck (so you know where I am coming from when I say the cruiser has plenty of power) A smaller less aggressive tire was not an option because of the trails I like to run.

 

[97cruiser]

Hello, Well I have never driven whitebird but I drive Lewiston grade, Snoqualmie, Stevens, Sherman plenty to comment. I have Cooper sst m/t in 285 and have no problems. Loaded for 4 days campin with 2 100 lb. labs in the back I go up lewiston grade at 45 shiftin between 4th and 3rd a couple times maybe.Same load goes over Snoqualmie at 65 mph Stevens at 45 headin east at steepest part.

Hope that helps! Vince

 

[PACNW96]

Hello, Well I have never driven whitebird but I drive Lewiston grade, Snoqualmie, Stevens, Sherman plenty to comment. I have Cooper sst m/t in 285 and have no problems. Loaded for 4 days campin with 2 100 lb. labs in the back I go up lewiston grade at 45 shiftin between 4th and 3rd a couple times maybe.Same load goes over Snoqualmie at 65 mph Stevens at 45 headin east at steepest part.

Hope that helps! Vince

That helps alot Vince...thanks! So if you aren't hitting 2nd on the Lewiston grade I should have no problems on Snoqualmie or Stevens. Basically, you are only shifting out of overdrive and maintaining a decent speed with some meaty MT's to boot. Good to know. Your post is leaning me even more toward 285's...

What speed can you maintain on the Vantage grade? I assume you could probably maintain 65mph.

Russell

 

[d0ubledown]

youll be fine with the 285's through the passes. if youre fully stacked, maybe go OD OFF and use pwr mode. that should keep the revs up and outta 4th to keep ya goin.

ive had both 285's and 315's...and the 1FZ has ample torque to handle either or reasonably. city & mountains included. dont expect any snappy pep off the line though...but with these rigs, you shouldnt anyway!

 

[97cruiser]

As long as no one gets in my way and I can maintain my speed i do 60 to 65 up Vantage fully loaded. I think you will regret not going to 285. If you decide to put new suspension on you will definately want 285 lifted or not. 285 seems to be the sweet spot.
I will also mention that my truck is running very well since I replaced my o2 sensors. Before that yes I would be downshifting too much.

Vince