For 285 owners w/ stock gears

[smallcandle]

This coming Friday I'm slated to get my Icon Stage 1 lift and BFG AT/KO 285/70/17's installed on my '12 TE. Having had experience with 33" tires on Wranglers in the past I'm a little concerned about how the 4Runner will tolerate those taller tires with stock gearing.

Specifically, for those owners running the 285's with stock gears: how does the vehicle respond when travelling up moderate sized hills? I'm curious to know if the transmission is constantly downshifting to keep the power up.

I'm fully aware that when doing a lift and larger tires there are certain trade offs. At this point I would just appreciate knowing how the engine and transmission are going to respond.

Thanks again for the patience - hopefully this will be the last question I have regarding how larger tires effect the stock gearing in our trucks.

 

[mrvandelay]

I haven't noticed it gear jumping but I can confirm it's obvious I have 33" tires... It takes a bit more throttle to climb hills. Admittedly, I'm in Florida - so hills are rare.

 

[Mick1]

:redbrick:

Broken record here.

I SUGGEST YOU ONLY CHANGE ONE THING AT A TIME

Do the lift, then drive it for a week or so to make sure everything is working properly.

Only THEN do the tires.

This will help you figure out what changes are resulting in what felt results.

Also, if you get a vibe or anything else wrong you'll have no idea if it is the tires or the lift if you install them all at the same time.

Other stuff you'll need to do.
Adjust headlights for the lift.
With non-stock tires you'd need a scan guage so you or anyone that drives the vehicle could easily see your actual speed.

Regarding the effect of the 285's, I'm not sure. I am still running 265's duratrac's and don't see a need for the ever so slight increase in ground clearance.

285-265 = 20 mm wider tire. 70% aspect ratio = 14mm taller tire / 2 = 7mm increase in ground clearance. Gee 7mm that is less than a lowly 9 mm round, we are talking .276 caliber difference. Not much. Heavy duty skid plates protect you a whole lot more than 7mm increase in ground clearance. However, the wider and heavier tire does affect mileage and handling.

(EDIT: it was pointed out that my math was off.

I confirmed, and pulled this from the miata tire calculator: http://www.miata.net/garage/tirecalc.html
265/70-17 7.3in 15.8in 31.6in 99.3in 638 0.0%
285/70-17 7.9in 16.4in 32.7in 102.8in 617 3.5%

So it is .55" increase in ride.)

That is the best advice I can give. If history is any guide, you'll still have everything done all at once and be back here in a couple weeks asking about how to figure out what is causing the vibes / rubbing etc. that occur as a result.

 

[Intruder]

Specifically, for those owners running the 285's with stock gears: how does the vehicle respond when travelling up moderate sized hills? I'm curious to know if the transmission is constantly downshifting to keep the power up.

I drive in the mountains a lot and don't really notice anything. You adjust to any minor difference over time anyhow by either giving a little more gas or speeding up before a hill climb.

I SUGGEST YOU ONLY CHANGE ONE THING AT A TIME

Excellent advice. Even if you don't like the look of the lift with 265s it ain't gonna kill you to drive like that for a week or so.

 

[GrantK]

I think I qualify for driving in a hilly area and have 285/70-17s. I don't notice more down shifting, just a little sooner than with stock tires. It was minor enough that I hardly noticed it when I first put on the bigger tires. Now I'm used to it and don't notice it at all.

As for the speedometer, mine was reading high with stock tires and now is right on the money based on several of those road side 'check you speed' setups that you find around town.

 

[smallcandle]

Thanks, Grant. I'm fully prepared for the truck to need to work a little harder to turn the taller tires. I was just trying to get a sense of what to expect as far as performance went.

Thanks for everyone's advice. Very excited to get the process started and enjoy the results! Pics will be up in less than a week...

 

[BigredTEX]

I bought my 2012 TE with a 3" OME lift and 285/70 BFG Mud Terrains. I never had the chance to drive it in stock form, so I have nothing to compare it against. However, I took a trip to Colorado this summer and was quite frustrated by the constant downshifting on the highway. Around town and in the mountains I don't really notice it, but the taller tires, along with the added drag of the tires and wind resistance of the lift do make a difference at highway speed. The slightest incline forces a downshift. Cruise control is rendered useless on anything other than table top flat roads. On rolling highway terrain I generally left it in 4th gear at an indicated 70 mph (which is actually approx. 74 mph).

Don't know if this helps, but just my observations.