Too Many Tire Sizes?

[fdcg27]

Since the government is always seeking to protect us, maybe NHTSA should regulate tire sizes.
A dozen or so different sizes would be enough for every consumer vehicle sold.
The big rim low profile tires are more about style than performance. Performance cars rode on and did well on higher profile tires for decades.
There would be a real safety benefit in this since tire makers would have only a handful of sizes to make and good tires would then be available at good prices for all.
The oddball sizes are a problem, in that quality replacement tires can be hard to source at any reasonable price.

 

[CapriRacer]

Originally Posted By: fdcg27
Since the government is always seeking to protect us, maybe NHTSA should regulate tire sizes......


NHTSA sees their job as saving lives - and tire sizing isn't one of those things that drives highway fatalities. They are absolutely not going to get involved with something that is going to be a quagmire and have no benefit.

 

[Traction]

Maybe NHTSA could save a few lives. If there wasn't so many different odd ball sizes you would have a lot better chance of finding better tires for the conditions. It's like out of control now. None of the manufactures want to standardize anything. Wheels for example. Why would GM come up with a 132mm bolt pattern that no one else uses. Lack of tire availability, and tire choices only add to the costs, and decrease safety. And, 25 series tires, or anything where the wheel is only 1 inch off the road should not even be legal.
NASCAR has been using the same size 15 in tire forever, with pretty good performance for the conditions.

 

[eljefino]

I think the new lug patterns are to force TPMS-equipped rims on us. But yeah it's dumb. My MIL's buick has a weird 5x115 or 5x120 pattern that's only shared with BMW. One more thing they didn't think through for those in the snow belt.

 

[Jarlaxle]

Weirdest is Ford: the F150 heavy-half used a 7-lug wheel.

Then again...my Dakota uses a funky 6x4.5" setup. Only ever used on Dakotas, Durangos...and Vipers.

 

[Spazdog]

Originally Posted By: geeman789
Friend has a Mazda CX-7 ... came with a 215/70/17 size tire...

He was looking for a winter tire, and had one choice .... a Blizzak DMV-1... ! Which was out of stock... of course.

I know of no other car using that size... did Mazda really have to use some odd-ball size...? Or do they do this accidentally on purpose...?



That is one of the unfortunate aspects of Mazda - oddball tire sizes

When the Mazda3S was introduced, it used a 205/50R17. Only two other cars used that size at that time. The Neon SRT/4 and PT Cruiser GT.

Same thing with my Mazda6S. I think only the 3rd gen Eclipse GT used that size.

They must be getting the tires at a discount price from the manufacturer because the tire manufacturers know they will be one of the few companies providing that odd size for awhile.

You can Plus-Zero size them pretty well. My speedometer is fairly close to accurate with a Plus-Zero tire.

 

[Jarlaxle]

I still remember the reactions I got when I asked for a 195/70R13...

 

[geeman789]

Originally Posted By: Spazdog


That is one of the unfortunate aspects of Mazda - oddball tire ...

They must be getting the tires at a discount price from the manufacturer because the tire manufacturers know they will be one of the few companies providing that odd size for awhile.

You can Plus-Zero size them pretty well. My speedometer is fairly close to accurate with a Plus-Zero tire.


Interesting point about tire manufacturers... if you tweak a size just a bit...and you know that no one else uses it... you create a monopoly ... the car maker gets a better price, and the tiremaker gets all of the oem and replacement business for awhile at least...

The 215/70/17 size mentioned earlier has exactly ONE listing on TireRack... only one... and it is a winter tire.

Another problem is that some owners WILL NOT buy a different size, period. They think the car will somehow self-destruct or auto- crash if tire size is changed... and the tire shop can take advantage... yep, there is only one tire in that size , and it's EXPENSIVE... sorry... or refuse to offer a different size for liability reasons... nope, you CAN'T change the size, it's illegal...

Almost bought a Toyota Venza .... then priced out the 19 and 20 inch tires ... then bought something else...!

 

[PandaBear]

My IS came with 255/40/18 in the back, and I decided it is all a bunch of bulls and mount 245 40 18 instead. Much cheaper.

 

[SubLGT]

Here are some more new sizes:

"………..Here are three new Load Range E flotation sizes that independent tire dealers can expect to see in their shops within the next three years.

1. 37x12.50R22LT.

2. 35x13.50R20LT.

3. 38x13.50R20LT.

If you have been waiting for a Load Range M 445/65R22.5 wide-base truck tire, that, too, is available……………………"

http://www.moderntiredealer.com/news/sto...tire-trend.aspx

 

[Jarlaxle]

I have been seeing 445/50R22.5's on trailers for a while now. Also seen 425/65's.

 

[Mr_Joe]

One has to plan ahead. The local shop may very well not have your size on the rack.

Most 'tire people' want to plan ahead anyway, to get the tires they want.

 

[Joel_MD]

Originally Posted By: Rand
Originally Posted By: Finz
Originally Posted By: Eddie
In addition a slightly narrower tire does better in water because of less tendency to hydroplane. ed


... And snow. Cuts thru instead of riding on top


That's very general, I could also say a wider tire does better in the rain.. more traction.

Or A wider tire is better on packed snow.

usually the differences are minimal and amount to personal preference.

Neither choice is right or wrong.

This seems to be a pretty common misconception. Wider tires and/or lower tire pressure give better traction on dry pavement and off road in mud or sand. Narrow tires and/or higher tire pressure are much better on snow and rain.

 

[CapriRacer]

Originally Posted By: Joel_MD
This seems to be a pretty common misconception. Wider tires and/or lower tire pressure give better traction on dry pavement and off road in mud or sand. Narrow tires and/or higher tire pressure are much better on snow and rain.


It's a bit more complicated than that.

Lowering the pressure will give better traction, but hurts the steering response time, making the car feel imprecise - and the net effect is slower lap times.

Then there is a point where the lower pressure decreases the traction, because the footprint gets distorted.

On the other hand, the reason higher inflation pressure works for snow traction is because the pavement has way, way better traction than snow and the higher pressure is more likely to penetrate through the snow to get to the pavement. HOWEVER, if the tire CAN'T get to the pavement, then lower pressure is better. That's why many folks have experienced lowering the tire pressure to extract themselves from a snowbank - and then they think lower = better, which is wrong most of the time.