20" tyres - Maintaining Factory Load Ratings

[dan444]

I'm wanting to put 20's on mine, but how do you guys maintain the factory tyre load ratings of 94 with 20" tyres, or any other low profile size from 18's up for that matter.

The rears at 275/30/20 are fine with heaps of tyres available at 97 load ratings.

The fronts however, the only 245/30/20 tyre with over a 94 load rating is a Nankang NS2 with 95. Doesnt make sense to me considering ALL the other manufacturers tyres (Pirelli, Bridgestone, Dunlop, Toyo, Kumho, Hankook, Yoko's, Falken etc.) of the same size are only rated at 90.

How do you guys get around this??? What are the side effects of running a lesser load rated tyre??


Cheers
Dan

[ems3s]

Plenty of tyres available with higher than 94 load rating in 18+, just not base model types. You'll have to go more expensive spec.

Running lower rated tyres becomes a roadworthy issue, also your insurance my be voided if they wanna be that anal when making a claim.

[ems3s]

Also what width are the rims you plan on using. Might be a different tyres size more suited to your rims than 245/30

[rhetto]

dont ever go under the load rating on your tyres placard,i found out the hard way as tempe tyres sold me a 235/30/20 88y and the tyres split on the inside of the tyres with under 5000kms on them,i removed the tyres and found out they sold me the wrong load rating and they said it was my fault. as that was the tyes they supplied me with when i told them what car i had.After 2.5 months of sorting this out,they refunded me the $500 for the 2 tyres and i bought a 245/30/20 tyre that ive had no issues with.Dont do it

[ant_jzs160]

^ im going to disagree with rhetto and em3s from my personal experience.

in some widths and sizes you cant get the right load rating. i looked high and low and at every brand and couldnt find anything. but i am stretching my tyres onto my 19s. even so, there just wasnt the right size and load available.

as for load ratings, try to get as close as possible. i have nexen n3000 all round on my car. front 19x9 with 235/35 91Y and rear 19x10 with 245/35 93Y. Now, the way i researched it is this. i looked up similar sized cars such as HSV Commodres and FPV Falcons, which are as big and as heavy and in comparison to my car are also faster and more sporty. i cant find it now, but i remember coming across somewhere that they only have like 92 load ratings compared to 94 for our cars.

nxt i looked at the load ratings themselves which relate to kilograms. see this link:
http://www.tyrepower.com.au/tyre_load.aspx

so then i did some maths. i got the weight of my car and divided it by 4 to see what load would be on each tyre as a dry weight. then i multiplied out the kg amount for a 94 rated tyre and worked out the difference. in my case, the difference was 1000kg. So basically, the 'room for error' is 1000kg. So basically it seems to me they planned the load rating based on having like 5 people in the car, a full tank of fuel, a boot of luggage and doing high speed! When doing the maths on the commodores etc, they have a 'spare' 800kg at dry weight.

then i worked out mine and decided overall it should be okay. not ideal, but okay. And i have had the tyres and wheels on the car for about 16mths without an hiccup driving the car daily in traffic and at highway speeds (which is my commute each morning and night)

as for sidewalls splitting and shit like that, the BIGGEST contributor to that is tyre pressures. if stupid tempe tyres put 88 rated tyres on a heavy car then put 35psi in them, they would be squashing out too much which heats the sidewalls and cuases blowouts. i keep my tyres at around 45psi or so, sometimes a touch less. max psi on these is 50psi. The higher the pressure the better the load rating as the tyre is harder, and nexen n3000s are an 'extra load' type tyre as indicated on their sidewalls. So regardless of what tyres you get, monitor your pressures closely.

hope this is of some assistance

[dan444]

So Rhetto, what brand / type of tyre did you go with??

I've only been able to find Nankang NS2 and Maxxis Z1 in the size I'm after that complies as they both have a 95 load rating.

[rhetto]

i went for the ns2 245/30/20- 94 up frt on the kuhmo 275/30/20 -97 on the rear.i had ns2 up frt 235/30/20 that failed.Well the people that designed the car and to comply with the correct tyres(load rating) for our cars would no alot more than any of us.The tyres i had the issue with was sent to me was 40psi in all tyres from tempe and never dropped below this pressure.The reason i no this is because i check my tyres with a tyre pressure gauge every week and ive never had to put air in the back or front,never had a punture.But its funny cause i had the same tyre brand on the front and rear and only the tyres on the front have split.Thats why the tyres have split cause the tyre company kumho that i had to send the tyres back to investigated into why these tyres did so and they said the weight of the car was to great and the tyres should have never been put on that car.tempe will have to pay you the money back for there stuff up and check the cars load rating before sending you out wheels and tyres for your car.Theres that tyre load rating placard on the inside of your jamb that tells you 94.a:the car will not be insured if you have a accient and the inspector sees this when he checked the car over.b:your putting you safety at riskc:your car should not pass roadworthy.Im running 20x8.5 up frt and 20x 10 on the rear with no clearance issues or load ratings now