On AWD vehicles it is recommended to change all 4 tires at the same time to prevent damage to the differental. But unless I am mistaken, my Buick Rendezvous only engages the AWD in certain circumstances, the car is primarily a FWD vehicle. In this case is it OK to replace 2 front tires if the 2 rear tires are good?
Go to the owner’s manual.
Do you move a shifter or push a button to engage AWD? If no, then your car is AWD and automatically determines where to put the power. You should always have 4 matching tires or your AWD system can suffer damage. Expensive, you don’t want to go there damage.
Most AWD systems only engage under certain circumstances. Even if the manual doesn’t explicitly state to replace all four tires (which it probably will state), I would still replace all four just to be safe. This is why tire rotations are especially important with AWD vehicles to keep even treadwear as well, in addition then they’d need to be replaced around the same time anyway.
I would have to check reference material to give an answer I am comfortable with. I do think this is an area that takes away greatly from the desireability of AWD vehicles as who wants to be saddled with the burden of a complicated tire replacement requirement? I can see this requirement being in place at the inital introduction of these type vehicles but it is a 'quirk" that should have been enginnered out of the vehicle or at least made so no damage will occour if a mistake in tire replacement is made.
[i] is a 'quirk" that should have been enginnered out of the vehicle[/i] I would expect that if it were possible, someone would have figured it out by now, but I know of no AWD that will not be damaged by tyres of even slightly different size (wear) Note, it is possible to shave the tyres that are less worn to match those that are more worn. If it were mine, I would buy four good winter tyres now and put them on a set of steel whees then, come spring, four good tyres for summer or shaved as indicated above.
In the end it is vehicle specific.
AWD means so many things across different vehicles. In Subaru and Audi it means you will have power going to all four wheels and excellent traction at all times. These a very mechanical systems that need close matched tires.
A Toyota and Honda after the vehicle is slipping based on electronics it engages power to the rear wheels. The problem with these electronic slip detection systems is they depend on tire speed. If the tire size is off against its peers again the system does not work properly.
In the what is SO complicated about replacing 4 tires? Expensive if early, yes, complicated by no stretch of the imagination.
Complicated enough that more than one person writes in asking that it gets explained too them. When something like "do I need four tires replaced or just two or just the one that got a sidewall puncture in needs explaining, things are complicated.
I don’t think that the ultimate plateau in AWD engineering has been reached, the tire situation clearly demonstrates this.
I would replace all 4 tires at the same time.
If the wear is greater on the front, it implies that you don’t rotate tires. It’s very important to rotate your tires so that they will be about the same diameter, since this is an AWD car.
“I don’t think that the ultimate plateau in AWD engineering has been reached”
I think the ultimate will involve an electric motor at each wheel, and electronics to sort everything out.