My Car Needs New Tires


#1

My car, a Lexus SC430 needs new tires. I have two questions.

First, can I replace these with regular tires and forego run flats?

Secondly, can I increase the size of my tires and buy 20 inch tires in place of what I currently have which are 18 in. tires ( I think).


#2

for the best answers see your dealer or a good tire dealer…minimum you will need four new wheels, check tirerack.com for regular tire size and recommendations…


#3

Yes, you can forgo the run-flats…Converting to 20" tires (why??) will cost you around $2K for a new set of wheels and tires. These super-low profile tires have such narrow sidewalls, they deliver a noticeably harsh ride and are subject to pot=hole damage to both tires and wheels…


#4

Yes, you can buy regular tires instead of run-flats. Keep in mind, however, that you will not have a spare. Somehow I don’t think you will be changing a flat tire by the side of the road, no matter what, so I doubt that’s a huge concern. Many people replace run-flats with standard tires.

The only way install 20" tires is to buy 20" wheels along with the tires, and that will be very expensive. There is no benefit to larger diameter wheels and tires, and they will probably reduce your gas mileage due to the higher weight of 20" wheels.

I would keep the standard wheels and just buy new tires.


#5

What kind of tire is a “run flat?” Sorry, but I’ve never heard the term.


#6

Tire Rack has a good explanation.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=56

Run flats are also known as self supporting tires. They’re capable of maintaining their shape and attachment to the rim after puncture and loss of air pressure…


#7

Okay, I called my dealer, but they recommend I don’t switch over to regular tires, otherwise it will throw off the computer signal that tells me when my tire pressure is low, etc. Run flats cost so much $$$!!


#8

A competent mechanic should be able to disconnect the tire sensors and spoof the computer. They view you as a cow being lead into the milking parlor…The manager of a good tire store should know what is possible and what is not. But remember, he wants to sell you those expensive tires too…


#9

Tire pressure monitoring is currently a requirement on all all wheels on all passenger cars. So for whatever size and style of wheel and tire you are considering that are allowed on your car, you should be able to get the valve stems that have the needed transmitters in them. That assumes the valve stems you have cannot be transferred to new rims, which is a possibility.

Car dealers are NOT usually the best place to ask about replacement tires. Call or go to an actual tire dealer like Goodyear, STS, Tirerack.com or whatever your choice. They will definitely be able to help you.


#10

I think the dealer is lying. The tire pressure monitoring system has nothing to do with whether the tires are run-flats or regular tires.

It’s perhaps not the best idea to buy tires from the Lexus dealer. They will do their best to sell you a run-flat, since that’s what the car came with.

Do yourself a favor, and do some tire research at TireRack.com. Don’t take the dealer’s word. Instruct yourself. This is not rocket science, it’s just tires, and they are fairly simple.

You can save a lot of money by going with regular tires instead of run-flats, and the odds that you will ever have a flat tire (when was the last time you had one?), are close to zero.

Save your money.


#11

Do you really want to advise to spoof a safety system?


#12

When did this requirement go into effect? I have not heard of it, and I’m unaware that ALL new cars have to have a TPMS.

Please enlighten me.


#13

49 CFR Parts 571 and 585 Federal Motor Vehicle Safety Standards: Tire Pressure Monitoring Systems; Controls and Displays.

Final Rule in PDF (222 pages 3MB)

The actual enforcement date is all light duty vehicles built from September 1, 2007 onward. Typically that would be the 2008 model year.


#14

Well, it’s hard to argue with that. Thanks for the information. I always like to learn new things.


#15

I think the dealer is lying. The tire pressure monitoring system has nothing to do with whether the tires are run-flats or regular tires.

I agree. I don’t think it can tell which type of tire it has. Just what the pressure is. Personally I’ve only met ONE service manager who knew the first things about cars. Most were flunkies who didn’t know the first things about cars…but have this great ability of SPIN.


#16

There are actually two types of run flats. One has stiffened sidewalls designed to provide minimum supprt without air and the other has an inner “doughnut” on the wheel to support the tread portion of the carcass without air. The first can be put on regular wheels, and can be swapped out with standard tires. The second cannot.

I do not know which type this vehicle uses, but he OP should check before making any decisions.

If you do go with regular tires, an old-fashioned chrome spare tire mount on the trunk lid might look cool. It would be a “retro” touch. You may start a fad.


#17

Safety System? It’s just something else to go wrong and cause problems…As it turns out, the lady can buy standard tires without any angst or hand wringing. No need to spoof the computer. We don’t need nanny’s Barry…You drive a car, you accept the risks involved. Lawyers and insurance companies worry about tire pressure monitors…


#18

“If you do go with regular tires, an old-fashioned chrome spare tire mount on the trunk lid might look cool. It would be a “retro” touch. You may start a fad.”

If the OP does that, instead of needing a tow truck when she gets a flat tire, she’ll need the tow truck to open the trunk.