215 wide tyre on a 2 ton car

[GSLex]

Hello my friends,

I own a Lexus LS430 and I am calculating to mount a 215-50-18 wide tyre on front the car.
The back will get some 225 tyres.

The original spec is 245-45-18 or 225-55-17.

Since the car is very heavy (1,9 tons) + I added a lot of sound isolation I want to know if that 215 is a safe size because its narrower then whats original adviced.

The reason I need to go this narrow is that I bought some very cool and wide Japanese 3 piece wheels which are quite wide. I need the hight of the tyre to keep the comfort. Comfort is for me a very very important element. I was planning to go for 245-45-18 but that will most likely rub the wheel arches.

I am playing with the thought to give the rear 225-50-18.

 

[skyactiv]

Tire weight ratings are listed by the manufacture. Some tires, usually low profile tires, are available or come in XL known as extra load.
Sidewall height is what generally adds weight carrying capacity to a tire. Old American pick up trucks from 50 years ago came with narrow tires that had very tall sidewalls which gave them weight carrying capacity. A 225-50-18 XL tire is rated 1709 lbs in the U.S., while the standard load version in the same size is rated 1521 lbs.

 

[Jetronic]

look at the type plate, the maximum axle weight is listed there for both front and rear axle. if the 215/50r18 has over half the load carrying capacity it can work (2 tyres so each carries half).

 

[SwampSurvivor]

HD trucks ran 215/85R16 for years ...

 

[GSLex]

Thanks for the reply guys! Ill check it out and I think this will work.

 

[AZjeff]

Diameter is exactly the same but 30mm narrower. Nobody can tell you the load rating of the tyre spec'd on your car and the ratings of whatever tyre you're thinking about. Match the load ratings and you're good. Seems odd to get very cool wheels and put 30mm narrower tyres than stock on.

 

[eljefino]

Look at the certification plate on your B-pillar (inside the drivers door.)

Assuming it follows American convention, it'll list the tire sizes and load ratings. You seem to need a 245/45R18 96V, the 96 is the load rating of 1565 lbs. So get 96 or greater. Going with a taller sidewall generally gets you more load rating, so I bet you'll be fine if you stay with a 245 width. I'd reconsider going 30mm narrower, that's a lot. What's the cause of your rubbing concern, different back spacing?

You should also ensure your rim width is appropriate per the tire maker.

If you really want comfort you'd get much more by downgrading to a 17" rim. It seems you're caught up in the coolness of the 18s you just obtained.

 

[Jetronic]

It's not following the American convention. But the type plate has the maximum vehicle weight, maximum train weight and maximum axle weights listed. The tyres fitted must be able to handle the axle weights.

 

[Quattro Pete]

Hello my friends,

I own a Lexus LS430 and I am calculating to mount a 215-50-18 wide tyre on front the car.
The back will get some 225 tyres.

The original spec is 245-45-18 or 225-55-17.

Since the car is very heavy (1,9 tons) + I added a lot of sound isolation I want to know if that 215 is a safe size because its narrower then whats original adviced.

The reason I need to go this narrow is that I bought some very cool and wide Japanese 3 piece wheels which are quite wide. I need the hight of the tyre to keep the comfort. Comfort is for me a very very important element. I was planning to go for 245-45-18 but that will most likely rub the wheel arches.

I am playing with the thought to give the rear 225-50-18.

As was mentioned, typical load rating for a 245/45/18 tire is 96.
Typical load rating for a 225/55/17 tire is 97.

Typical load rating for a 215/50/18 tire is 92.

That's a big no-no.

 

[Jetronic]

215/50R18 XL are 96 aswell, but that means you have to run them at a very high tyre pressure, which doesn't help comfort either.

 

[GSLex]

Diameter is exactly the same but 30mm narrower. Nobody can tell you the load rating of the tyre spec'd on your car and the ratings of whatever tyre you're thinking about. Match the load ratings and you're good. Seems odd to get very cool wheels and put 30mm narrower tyres than stock on.

I havent found them jet but I keep searching for those numbers.

The new wheels are 9.5J ET12 in the rear and 8.5J ET0 in the front (ET12 actually but they need a 12mm spacer because of a fat brake caliper so its ET0 after all) It will just not fit if I use the 245.

Here is an example from somebody who I know and he sas about the same specs. He claims to have 10.5j in the rear but I am not 100% sure about that.

I extremely love this look but I want to have a high sidewall to keep my comfort so I need to stretch it a little bit.

 

[GSLex]

Look at the certification plate on your B-pillar (inside the drivers door.)

Assuming it follows American convention, it'll list the tire sizes and load ratings. You seem to need a 245/45R18 96V, the 96 is the load rating of 1565 lbs. So get 96 or greater. Going with a taller sidewall generally gets you more load rating, so I bet you'll be fine if you stay with a 245 width. I'd reconsider going 30mm narrower, that's a lot. What's the cause of your rubbing concern, different back spacing?

You should also ensure your rim width is appropriate per the tire maker.

If you really want comfort you'd get much more by downgrading to a 17" rim. It seems you're caught up in the coolness of the 18s you just obtained.

All other drivers of these cars mount 19 or 20 inch. My original 245-45-18 wheels and tires are really comfy and I am super happy with that. Thats why I keep these numbers as a reference. Thats why I have searched for about 2 years intensively for these rims. Normally there are no exotic rims in 18 inch. They are always 19 or 20 inch.

225-55-17 is also an original spec size so I am going only 10mm more narrow.

Check the picture above why it's rubbing.

Here are my calculations on this. I try to keep it around 110mm hight of the tyre so I keep the comfort. I understand that what I am doing is really rare because all the car people don't seem to care for comfort anymore and everybody is driving on super thin tyres and the looks are beautiful of-course but I want looks and comfort together and I am sure I will succeed

 

[GSLex]

As was mentioned, typical load rating for a 245/45/18 tire is 96.
Typical load rating for a 225/55/17 tire is 97.

Typical load rating for a 215/50/18 tire is 92.

That's a big no-no.

This is making things more difficult.

 

[GSLex]

215/50R18 XL are 96 aswell, but that means you have to run them at a very high tyre pressure, which doesn't help comfort either.

Interesting. Ill restart my research on this size again.

 

[GSLex]

Well. The load isnt a problem on the 225-50-18. The Michelins I found were actually 99. The original 245-45-18 tyres which I have right now have the same so thats great.

Only the 215 width will be a problem. I only want to buy Michelin because these are the most silent. There are more silent tyres in the beginning but after a wile they start to make more noise and I know from experience that Michelin is really steady with this.

I think I should take those 225 all around and take no risk.

 

[Jetronic]

I think sticking to the same size front and back is definitely wise

 

[2EHA]

at the minimum i’d do 235. 215s look wacky

 

[CapriRacer]

You should be aware that:

1) Stretching tires onto wheels hurts ride comfort. So those wide wheels you so admire is going the wrong direction for ride comfort.

2) Going smaller in load carrying capacity requires more inflation pressure to get the same load carrying capacity. That is going to hurt ride comfort.

3) Using an XL is going to hurt ride comfort, because the XL requires more inflation pressure to carry the same load as an SL.

To my knowledge no one publishes a guide as to how big the fenderwells are on the many makes and models of cars that have been made. Further, the idea of using less offset to move the wheel further out would seem to mean that the fender would be the limiting factor. Tire rubbing is extremely bad, so avoid that at all costs!

 

[4WD]

Discount Tire | Tires and Wheels for Sale | Online & In-Person

www.discounttire.com

 

[GSLex]

I think sticking to the same size front and back is definitely wise

I hope it looks nice!

at the minimum i’d do 235. 215s look wacky

Maybe you are right....

You should be aware that:

1) Stretching tires onto wheels hurts ride comfort. So those wide wheels you so admire is going the wrong direction for ride comfort.

2) Going smaller in load carrying capacity requires more inflation pressure to get the same load carrying capacity. That is going to hurt ride comfort.

3) Using an XL is going to hurt ride comfort, because the XL requires more inflation pressure to carry the same load as an SL.

To my knowledge no one publishes a guide as to how big the fenderwells are on the many makes and models of cars that have been made. Further, the idea of using less offset to move the wheel further out would seem to mean that the fender would be the limiting factor. Tire rubbing is extremely bad, so avoid that at all costs!

Thats why I want to go for balloon tyres like a 50 hight! I want the best of both worlds. Thats why I went for 18 wile the whole world is riding on 19 or 20 (The VIP Car build world I mean)

The 245-45-18 which I have right now are XL. I just found out... I never looked that up but I was very happy with those tires... extreme comfort. I was always driving on 2.4 bar all around. Whats your opinion on that pressure?

I am sure that I need to cut and roll my fenders but I dont want to roll them to far but I cant accept any rubbing. I am extremely precise on those things.