RX8 Alloys, what tyres?

[ns400r]

Hi

I have got some RX8 alloys which need tyres.
The tyre choice I have seems to be down to two sizes,

225/45/18 96 or above

245/40/18 96 or above


I wonder what the pros and cons are, I notice there seems to be more of the 245/40/18 available in the higher load rating, also more in general and some really cheap budget ones on EBay.


Any comments would be very helpful.


Clive


1999 Ford Freda 4x4

[mister munkey]

I've 225/45's on my RX8s



Some have 245/45's which I was dubious of with regards to rubbing the front arches on full lock but apparently they fit fine.

The 40's look too skinny for my liking, even with the 45's the wheel arch gap looks too big.

Next time round I'll go to /50's.

[francophile1947]

245s seem to be cheaper, but will give a slightly harder ride due to the lower profile.

[You've Been Bongod]

my 18's have 225/40/18 98 rating £50 ish per tyre
and they were from wheelquick so i will stay with that size because mike knows best


you've been bongod

[cheffy34]

Iv'e never found a 225/45 with a 96 load, best i've ever got was 95 extra load, gone for 245/45 on the rears now 98s says nowt in my doorpost about 96s recommends 98s on rear, mine is 2wd v6 tho quite like the look of it now with the bigger on the rear just want one with the tyre protector on them like the bridgestones on front, i found part worns a good way for me mainly cos my mate does em for me at special mates rates

[ns400r]

Hi

225/45/18 seem closest to the original rolling diamater, then 245/40/18. Also, won't these 2 look very similar when in the wheelarch because they have a similar overall circumfurance.

However 245/45/18 seem quite oversize - is this a problem? I know it will make my speedo read inacurately.

Thanks,

Clive

[mister munkey]

Unless I've been wrong for years, the 225/245 bit is the width of the tyre, the 40/45 number refers to the height of the tyre wall. i.e. the higher the number, the wider the outer diameter of the tyre circumference.

A 225/45 will have the same rolling diameter as a 245/45 & give the same speedo reading as only the width is different - but a 225/40 will, in effect be smaller & read faster - surely?

[ns400r]

This is the wheel sizing program I have been using.

What do you make of it?

http://www.1010tires.com/tiresizecalculator.asp


clive

[splitpin]

Not quite right mister munkey, the 245/45 will have a larger circumference than the 225/45, this is because the sidewall height is given as a percentage of the tyre width. So 45% of 245 is 110 mm and 45% of 225 is 101mm, making the 245 tyre approx 18mm larger diameter than the 225.

[mister munkey]

Ah Ha!!

Makes sense. Many thanks!

[waycar8]

using the tyre calculator,

if your going with 245x40x18 this gives you a Diameter Difference of 0.12%, compared to 195x70x15

if your going to go with 225x45x18s then you get a Diameter Difference of 0.89% compared to 195x70x15

but by going with 245x45x18 then you get a Diameter Difference of 3.53% again compared to the 195x70x15 front tyres and wheels, which is bad acorfing to the calculator glad i didnt win the set i was biding on tuther day

so i will now be going with 225x45x18 for a fatter tyre to fit the arch better even thoe the 245x40x18 gives a more acurate rolling circumphrance matched to the bongo.

[mister munkey]

Hassle the man Wayne.

He's possibly well p*ssed off he didn't get £400 for those wheels & wants you to ask for your money back so he can re-list them with the correct spelling.


Go get him dude, thats a bargain!

[HiddenMission]

I've been searching for tyres (225/40 or 225/45 with 96+ load rating) for my 18" alloys and have only found Yokohama and Hankook on the web - my local mobile tyre specialist (who seems pretty knowledgeable) has been unable to source anything at all.

I'd be interested to know if people have actually managed to find suitable tyres, particularly if they are less than £100 a pop, and if so from where. I had a look at the Wheelquick website, but they don't seem to list tyres.

Also, can anyone say that their tyres are tried and tested? I've been through several sets of the wrong tyres, so I'd really hate to source the "right" tyres only to find that all 4 need replacing after 9 months.

[francophile1947]

Same problem I had when considering 18" wheels. I could only find load ratings of 92 for the 225/40s and 95 for the 225/45s

[WISHIHADABONGO]

I have 95 rated tyres on mine 225 45 18, was the cheapest and closest I could find I paid £50 fitted each and they have been spot on, I admit I have only done 2000KM but I have even wear all round and no scrubbing perfect.

I am selling my van so will be doing a swap for standard wheels plus some cash at some point...