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whats the best tyre size to put on for 20 inch wheels?

Discussion in 'General' started by James, Dec 28, 2011.

  1. James

    James New Member

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    Hey everyone,
    Just bought some 20 inch chrome wheels and was wondering whats the best tyre size to put on?
    235/45/20's? or what?

    I have a holden commodore vy s series 2.

    thanks alot!



    new question :

    whats better and the difference between - 225/35/20 & 245/30/20 , as it says both are able to be used for 20's.

    I have a 04 VY Series 2

    thanks
     
    Last edited: Dec 29, 2011
  2. ben315vz

    ben315vz Donating Member

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    235/30R20 is the size you need.

    If you put 235/35R20, you will think the car is using heaps more fuel, and also lack power, but mainly, it will scrub and rub on your front struts.

    I damaged a guard on my WH Statesman by putting the wrong tyre size on.
     
    Last edited: Jan 15, 2012
  3. axemurderer101

    axemurderer101 Well-Known Member

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  4. James

    James New Member

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    thanks guys
     
  5. James

    James New Member

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    guys whats better and the difference between - 225/35/20 & 245/30/20 , as it says both are able to be used for 20's.

    I have a 04 VY Series 2
     
  6. axemurderer101

    axemurderer101 Well-Known Member

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    245/30/20 are a wider tyre so they wont be as stretched if you have 8.5inch wide rims, these may rub on your front strut towers depending on the offset of your wheels so some people go the 225's instead. main issue you have to worry about is the load rating on the tyres because if the rating is lower than the tyre placard you could get defected.
     
  7. TMM

    TMM OEM+

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    You will find that 245/30R20 is the only size with a legal load rating (91+). You will need a wheel with a low enough offset for the tyre to clear the strut, or coilovers which have a slimmer spring/strut. Front guards will need to be rolled and possibly slightly pumped/flared if a wheel with a low offset is used.

    Standard offset is +48, something like +30 would mean the wheels 'stick out' 18mm more than standard. I'm not sure how low an offset you need, maybe someone else will know :p

    225/30R20 avoids all these issues, but is illegal (load rating is 90 or lower, which is too low) and you will get a defect. This is pretty much the first thing the cop will check (tyre load rating) when they pull over a Commodore with 20" wheels.
     
    Last edited: Dec 30, 2011
  8. James

    James New Member

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    I have these wheels available 20 x 8.5 alexia gestalt : products

    So i can only use 245/30R20 to not get defected? Also are 20's are legal on 2004 VY S Series 2?

    And how hard and whats the cost to roll the front guards.

    Thanks
     
  9. TMM

    TMM OEM+

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    Yes and Yes.

    If you look on the inside of your drivers door there will be the tyre placard. On the placard it will have a list of wheel/tyre sizes and load rating. Any tyre you use must match or exceed the lowest rated tyre on the tyre placard. I think your car will have 235/40R18 listed with a load rating of 91 as the lowest one, but go have a look anyway.

    Nankang 245/30R20 for instance have a load rating of 95, thus being legal. There are some other (more expensive) brands that also make tyres in that size and have a suitable load rating.

    There is a lot of misinformation about what size wheels are legal and what not. There used to be a 2" rule where you could only fit wheels that were 2" larger than the biggest factory wheels, so if say 17" was the largest factory wheels for a car, 20" would be illegal, but that law is now defunct. Even if it was still a valid law you would be fine because VYs came with 18s.

    The new laws say that the overall rolling diameter of the wheel/tyre must not be more than 15mm greater then the largest wheel/tyre listed on the tyre placard - therefore if you put big wheels on you must use low profile tyres, which makes sense. The standard 235/45R17 on a VY S-pack is 321.65mm, and a 245/30R20 is 327.5mm, so you are ok there :)

    There are also laws regarding wheel offset/track, but:
    a) i don't think anyone even bothers to enforce them
    b) if you had it wheel with enough offset to violate the laws, it probably wouldn't fit on the car with 245 wide tyres :p
     
    Last edited: Dec 31, 2011
  10. axemurderer101

    axemurderer101 Well-Known Member

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    is your car lowered yet? in most cases you wont need the fronts rolled it is mainly the back which needs to be rolled if your car is lowered
     
  11. Zeussy

    Zeussy SSM11K

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    Not true. 225/35/20 Achilles ATR Sport have a load rating of 93w which is what I used to run on my VY. Legally. One of 'few' (2 or 3) tyre brands that had a load rated tyre for them.

    4x 225/35/20 Achilles ATR TYRE FIT HOLDEN COMMODORE | eBay
     
  12. trent d

    trent d New Member

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    Tha biggest that will fit under the guards
     
  13. sweefu

    sweefu New Member

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    All this info is quite wrong, starting with the correct tyre size being 245/30R20 for a VY
     
  14. James

    James New Member

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    My VY S Series 2 is not lowered at stock height. (Though i wish to lower 50mm legally?)

    So what would be better the 225/35/20's or 245/30/20's?

    My tyre placard states : Load index of 92 and a Speed category not less than H. Max load rating not less than 630kg.

    And if i was to lower the car by 50mm what problems would this cause? Just need to roll the guards?
     
  15. ben315vz

    ben315vz Donating Member

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    The only part that can be wrong is that first line, because the rest is what I experienced with my own car so it can't be wrong.

    But a mistake I made was "235/25R20", that was mean't to be 235/35R20.

    I seriously thought something was wrong with my Statesman, I had plenty of power for a V6, then all the sudden it didn't want to go at all. I took it to another workshop and they done all the tests, fuel pressure, compression, hooked it up to a scope and a scan tool. Then when I went up a driveway and the L/H/F tyre pushed the guard out, I took the wheels off and put the standard ones back on, then it was back to normal, fuel usage was good again, power was back to normal, so I sold the tyres as VE tyres and bought new ones.
     
    Last edited: Jan 15, 2012

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