Interesting Article in Consumer Reports

[DBMaster]

I just got my latest issue of Consumer Reports and there was an article on "plus sizing" of wheels and tires. You can imagine what the tone was by the title "When More is Less."

They basically tested various wheel/tire combinations on a BMW 5-Series and a Honda Accord. It was a toss up as far as handling went between the factory combination. The "Plus One" (one inch larger rims, ten mm wider, and one aspect ratio lower tires) gave a slight improvement in handling , but a loss of ride comfort and slight loss of wet traction.

Going to the higher "plus" combinations actually started to worsen handling, significantly worsen wet and snow traction, and degrade ride comfort. They also did a pothole test and found that the lower aspect ratio tires on the bigger rims resulted in very easily damaged rims - DUH!

They summarized by saying that the plus sizing was safer for people who live in warmer climates with milder weather and that about the only benefit you get from doing this is looks.

I guess we all know about the tradeoffs in form over function. All in all I found this very interesting as I used to assume that the bigger tires automatically meant better handling.

[88LXi68]

I think the key word is the plus sizing RIMS. Bigger tires are almost always better for traction and handling. If they had tested 15" wheels with different size tires we would see the results would and should show bigger tires (wider) are better.

[NXRacer]

euro tuner did a similar test, but they were looking for different results.

With a bigger wheel and a lower profile tire, cornering and traction were improved, but in a drag type situation, the performance went down. The reason this is is because with a low profile tire, you have less sidewall roll so it improves your traction in cornering, but in a drag race, you need a little side wall roll so your tire has a chance to get grip.

the opposite was shown when they went for a smaller wheel with a taller tire.