On the 215/45-17 Bridgestone Turanza EL400-02 found on some Prius package Vs, there's a lip surrounding the innermost edge of the sidewall and it protrudes out in front of the 17" rims. It was the first thing I noticed when I got the car and thought it was pretty cool looking, but didn't know what, if any, purpose it serves. I looked at the high resolution picture of a Bridgestone Turanza EL400-02 and cannot find this "lip." Do owners of the Vs with Michelin Pilot HX MXM4 or Toyo Proxes A20 have this feature on their tires?
Yep - I have the 17" Toyos. Was pleasantly surprised to see the convex ridge all the way around. Must be a bit of defense for alloy wheel scrub on curbs... Nice design.
That's what I suspect, but is that all it does? It must also be tire size dependent because the hi-res photo on Tirerack doesn't have it.
It's a rim protector against curb damage. It's usually only on lower profile tyres (such as those on the "V". 215/45R17 are pretty sporty. They're found on sporty cars like the Lexus IS). You won't see them on smaller tyres.
Tideland, Your answer would be my first guess too. That said, I wonder if the ridge might also have an aerodynamic purpose as well, that being to direct the air passing over the rim/tires outward just a smidge and perhaps even bridge over the gap between the rear of the tire and the bodywork. Maybe a lucky Gen III owner could do some tuft testing and take pictures to see what the OEM airflow down there looks like.
It has nothing to do with aerodynamics--it's to protect the wheels on low profile tires. I've had it on all my cars for the last 10+ years.
The Scion wheels I just bought with those tires have them "lip" it is to rotect the rims from curb damage. I know for sure the Goodyear Eagle GT also has them in that size as well.
What stream said. It's not specific to the Prius. Most newer tyres of these dimensions will have a rim protector built in. They're not present on the same tyre model but of higher sidewall height and/or smaller tyre size.
Correct, and FYI my Lexus IS 350 (factory Bridgestone Turanza ER33) has it on the front 225/40 R18 but not on the rear 255/40 R18. It all depends on the tire and size, I guess.
Do all tires in a specific size (e.g. 215/45-17 on Prius V or 225/40-18 on IS 350) have the sidewall lip/convex ridge? Or does it depend on the tire brand? Better yet, how do I find out whether or not a particular brand/size has it? I spotted a new Mazda 3 with 205/50-17 Goodyear Eagle RS A and the tires lack the rim protector.
Put 2 new Cooper CS4's on the Camry and Express had a set of 4 Toyo Proxes 245/45ZR17 with the rim protector in the showroom, but the 235 width didn't. My mom's Infiniti G35 Coupe has Falken Ziez 512. Front 225/40/17 with rim protector and 245/45/17 rear also with protector. It seems the higher performance tires have them.
My guess, based on the on the front versus rear disparity on mine and the visual appearance (225 front 255 rear, all else the same), is that it depends on the vertical distance to the base of the wheel. Whether that's unique by tire manufacturer, or a common standard, I have no idea. Start with picture comparisons at a place like Tire Rack, if the picture is clear, or call them. They usually have a good handle on their products.
