I have been told by tire people that vehicles such as mine (7speed automatic tranny, rear wheel drive) are so sensitively balanced that when replacing two tires (say, front), that the rear should also be replaced lest the difference caused by uneven tire tread will ruin the transmission or differential. Tread depth currently is 3/32 in front and 6/32 in rear. Why can’t I just replace the front when 2/32 is reached and the rear later?
They should have told you that when buying 2 new tires only they always go on the rear . Apparently you have not been rotating your tires either. If this thing is all wheel drive then yes you need 4 tires at the same time. I would never let my tires get below 4/32 period.
You can. RWD and FWD cars are not hurt by different tread depths between front and rear tires. Tire store salespeople should know this.
The tire store employees know it…
It’s just an way to scare people and get the up-sale.
I too would never trust tires with less than 1/8 in tread.
This is a Mercedes GLE which, in some configurations, has directional tires and different sizes front to rear so it’s possible OP can’t rotate them.
I don’t see any obvious reason how a tire difference front/rear would affect the transmission or differential of a rear wheel drive (as opposed to an all wheel drive) car. Tire differences left/right could, but not fore/aft so much. It’s possible however that the braking and/or stability systems which use various sensors (like wheel speed, distance, lateral, and yaw) could be affected and that might confuse the car’s stability and braking computer. That’s the only thing I can think of. The tire experts you heard this from may have experience with this problem on Mercedes vehicles before and are just be cautious as applied to your particular vehicle. Suggest to inquire at a Mercedes dealership, they’d be in a better position. You don’t have to purchase the tires there of course, but they should know if there’s a problem with fore/aft tire differences. Mercedes makes so many versions of cars it would be hard to generalize how it would affect your particular car for the average tire expert. Best to seek out a dealership opinion. Suggest to ask if your tire purchases could affect the warranty also.
Directional tires can be rotated as long as they are the same size. Just rotate them on the same side.
$40k car with worn tires. And cheap owner?
Of course, but the point was the GLE, in some configurations, has different sizes front to back as well as directional which means all 4 tires are unique and can’t be rotated.
Is it possible that you have the GLE confused with a different model ? A tire search shows 2 wheel sizes but nothing about staggered and directional tires.
Maybe the OP will return and clarify and if not at least they will not let their tire tread get down to hazard level.
I’m easily confused, no doubt about that, but the GLE came in both an SUV and coupe. The OP didn’t specify which one they have. The coupe, in RWD (which OP stated vehicle has) has different tire sizes in the front and rear (see page 357 of owners manual). My point was that you can’t rotate tires on vehicles with directional tires that are different sizes in front and rear. If they aren’t directional, obviously you can rotate front to front and rear to rear. I just didn’t want to assume the uneven tire wear was the result of not rotating tires.
To my knowledge this is only true for a car with a viscous center differential, such as Subarus. With those, all tires have to be within close tolerance to avoid excessive wear and failure of the center differential.
and it is likely that the tires are not directional. Only the OP knows for sure. Also,Tire Rack shows no difference between front and rear tires. There are two tire sizes listed, depending on whether 19" or 20" rims are used all around.
Please see my above post. If it’s the coupe, and not the SUV, (OP didn’t specify), then it has different size front and rear tires. Tire Rack doesn’t even have the GLE350 coupe listed. They do have the GLE450 & GLE63 coupe listed and, yes, they show different front and rear tire sizes. The owners manual which can be found here, confirm the different sizes. Again, if it’s the SUV and some configurations of the coupe then, yes, tire sizes are the same in front and rear. My point all along was to cut the OP some slack as some people were giving the guy/gal a hard time about not rotating the tires when, who knows, maybe they can’t.
I seriously doubt if this OP had the AMG version they would want to run the tires down to almost no thread.
Ugh. Even the base GLE350 with 21" & 22" wheels (non-AMG) has different front and rear tires. Has anyone looked at the owners manual?