6fthook

Hello everyone,

My wife is driving a 1999 RX300 and recently got an unrepairable flat tire. We are trying to decide whether we want to replace all 4 tires or just 2 to put in the rear of the vehicle. Here is some info about the current tires:

Two of them were manufactured in 2010 and have about 50% tread life on them left (one of them has a tiny bit of dry rot starting on the sidewall), and the other one is 2008 manufacture with a good amount of dry rot on the sidewall. If we just replace 2 tires we're planning on putting the two 2010 tires in the front and the two new ones in the back (unless the opposite is better). All of them are Toyo Open Country A/T 225/70/R16.

The shop we went to is recommending to replace all 4 with Firestone Destination LE2 tires. If we only replace 2 he said he can get the Toyo AT2 tires. The owner/mechanic says he recommends all 4 because if we only replace 2 it's going to put a lot of stress on the transmission and could have future problems. The thing is, the vehicle has about 167,000 miles and we're planning on getting her a new vehicle sometime in 2014 or possibly 2015 and put the RX300 into reserve status.

Our questions are:

1. Would you recommend replacing all 4 or would be ok to replace just 2?
2. How big is the risk that if we only replace 2 will transmission problems occur?

Thanks!

hypervish

Welcome to Club Lexus!

First off I'd like to say the Firestone Destination LE2 is a fantastic tire! The reviews are phenomenal, and they are very budget friendly.

I'd recommended you go for a entire set of tires i.e all 4. Considering you may use it as a daily driver for maybe another year or two and then still hold on to it. If you were going to be selling it after a year or two, then I'd probably only throw two tires on the rear and call it a day.

The risk is not that it will damage the transmission, but rather the differentials and maybe transfer case. This has to do with the tires being different sizes (diameters change per tread depth), and the differentials having to make up for the difference. Well, that's my basic explanation anyways. Someone can probably go into that deeper if need be.

BTW, definitely put the new tires on the rear. It's crucial the better tires are on the back, rather than the front.

Dadikins

Is your spare an OEM (either Goodyear or Michelin) tire, or had the spare been replaced at some point with a Toyo?

Instead of getting 2 new tires, you may want to consider getting 4 Toyos if your spare is presently OEM & designating the better of the 2008 as the spare. That way, if you ever get another flat, you will have something with the same tread pattern.

We did this with our spare - many years ago, we got 4 Michelin LTX M/S. After around a year or 2, one of them got replaced under a road hazard warranty.

When we replaced those with 4 new Michelin LTX M/S2 (the original M/S was no longer made - was told the only difference was the type of rubber used), we had the tire that had been replaced under road hazard warranty assigned as the spare (to replace the OEM Goodyear).

yakev724

Could you please elaborate?

After reading the F/R drive balance was something like 70/30, I'd imagine the fronts are going through a lot more stress and therefore newer tires up front would be preferred?

hypervish

This video will show you what I mean:

code58

I realize most cars today arew FWD, BUT it does make a difference whether the car is RWD or FWD. America's Tire video is over simplified and incomplete info.

rxda90

I agree with you.

With the new tires on the front, they included a cut-in showing that the driver purposely held his hands firm and didn't steer out of the skid. Then with the new tires on the back, they called out the fact that you can still steer out of the skid. Well golly, couldn't he have done that in the previous trial?

Seems like they were trying like hell to get their point across, without really doing a controlled experiment to prove it.

hypervish

Michelin agrees they should be on the rear: http://www.michelinman.com/tires-101...ing-tires.page

As do Tom and Ray from the popular podcast CarTalk: http://blog.nwautos.com/2009/03/are_...t_or_back.html

Regardless of the drive type, the wheels should be placed on the rear.

hypervish

You can't steer out of a skid with new tires on the front because the it's the rear end that loses traction. That's the whole point of the video. To point out that if the rear end loses traction, there is nothing you can do. The steering wheel controls the front wheels, not the rear.

rxda90

I'm being critical of the "experiment" used to get their point across in the America's Tire video.

I would have preferred that they use the same car, under identical circumstances, and maneuvered the vehicle around the corner to the best of their ability at varying speeds to actually demonstrate the difference between the two scenarios. Let the data speak for itself.

I buy my tires 4 at a time, so I don't care.

Nice jab about the steering wheel controlling the front wheels. Hope you just forgot the smiley.

hypervish

Sorry you took that personally, but it wasn't meant to be a "jab".

yakev724

I think 1) the dynamics of the car in the video are model-specific and 2) the situation tested in one of many in which grip is tested and doesn't represent the several situations which may come up and force us to push our cars to their limits of grip.

To my first point, I would expect our RXs to be much more prone to understeer than oversteer in the scenario presented in the video. In that case, new tires up front would give the front wheels additional grip to help turn the car (as opposed to it skidding straight regardless of steering input).

To the second, imagine you're on a snowy/winter road approaching an intersection and the ABS kicks in to help you brake. I'm damn sure the car will stop sooner with fresher, grippier rubber over the bigger front brakes than on the rears, and will also give you additional front-end control over the slide.


I'm not saying the video is wrong...just that it lacks enough specifics to assure me that their conclusion applies, in any way, to our cars.

carguy07

I believe it to be true, but I still rotate the best ones to the front to try to keep wearing them evenly. But I never buy new ones 2 at a time, always a set of 4.

code58

I've driven for longer than I want to admit in many different brands and models of cars and trucks, both FWD and RWD. I worked in a job where we were required to view many different kinds of videos on safety, including some VERY good videos by the Ca. Hwy. Patrol on controlling (and bringing under control) cars under many different scenarios on many differnt kinds of road conditions. These were driven by Hwy. patrolman who knew exactly what they were doing. I learned a great deal from them and I stand by my original post!