Tyre size for 17" rims

[Grainger]

Hi all, Im a newbie here and would like a bit of advice if its not too much trouble.

2 months ago (new) I purchased a 2011 GU Patrol. ST model.

I have the nissan black steel bull bar, 9000lb warn winch at the front so I will be having installed koni shocks and king coils front and rear in the next 2 months or so - hoping for approx 2" lift.

I am wanting to upgrade my tyres keeping my 17" rims. I've been advised by a few tyre places that the 285/70r17 would be the biggest tyre I could have (and this would give me a little more lift).
I have seen on this forum and others patrols with 315/70r17 and some with 305's (not sure of the rest of the profile as I could not find it when writing this..doh).


I will be doing mainly road driving but will be frequenting Fraser/Stradbrooke and Moreton frequently - sand work, so will be looking at A/T rather than Muds.
I am looking for advice (from people that have larger tyre sizes preferably) as to what size I can get away with and recommendations of tyre brand also. I have been looking at the BFG's ?? I know these are recommended by loads of garages but am open to suggestions.

Many thanks for your time. Look forward to visiting the forums regularly.
Mark Grainger

[oncedisturbed]

285/70/17 = approx 33's

I have these on myine in the maxxis bravo A/t's and they are fine any bigger and there would be a few issues with guard clearance wtc unless a bigger lift is fitted

[MudRunnerTD]

Hey Mark,

for your style of driving and areas of travel a 285/ 75/17 will be perfect mate. You dont want a big lift on the beach anyway bud. Just not needed so a 2" lift and a set of 285s will get you where you want to go.

Remember that the bigger the tyre the more power they drain out of your car. Your diff and gear box ratios are set for a 265 and going to a 315 will pull the backside out of the car.

For beach driving you want all the power you can muster. When in Doubt? Let more Air Out!

[Grainger]

Thanks for the info guys, hey MudRunner - did you mean 285/ 75/17 or did you mean 285/70/17 ? I havent had anyone suggest 75 at this stage ?
Thanks again

[MudRunnerTD]

Probably 285/70/17 mate, 285/75 is in a 16 for a 33 so the 70 profile would likely be the 17 alternative for a 33.

[stets]

mudrunnertd, and grainger,

285 and 315 are the width of the tyres, 285mm and 315mm respectively, the width has no relevance as to how much power it takes to turn it. in fact the wider the tyre the easier it is to turn in sand as they tend to spread the weight more evenly. the second figure is the percentage of the width that makes up the height of the sidewall.

for example, 315/70/17 equates to a 34.4/12.4x17 so 315 is 12.4 inches wide, 70% of 315 is 220.5. so 220.5x2 +17 (431.8mm) inch rim= 34.36 inches tall on a 17 inch rim

305 equates to a 12 inch wide tyre and is usaully a 34" high tyre giving you a bit more diff clearance but more likely to rub on the vehicle

the higher the tyre, the larger the diameter, which requires more torque and power to turn, it also throws your speedo out a bit. the width does nothing except give you more traction

[MudRunnerTD]

Yes that is correct Stets. But the width of the tyre is most often the indicator of how big the thing is too. The second number, as you say and i noted in the previous post is the Profile size and your correct is a direct reflection as a %% of the width of the tyre.

a 285/75/16 is generally accepted as a 33 in the old scale and a 315/75/16 is a 35.

As long as old mate is looking at a 285/?(70/75)?/17 then he will be fitting a "33" inch tyre. I am not even sure if there is a tyre size 285/75/17? it may well be so, and you'd know better than i, that a 285/70/17 is the shelf stock size for a 17 in a 33.

Regardless, the most appropriate size that Grainger should be chasing is the 285 (33) for his style of off roading. ;)

Staying with a 33 will see the engine still being able to handle the task without the need to look at diff ratio changes or gear box reduction gears.

[MEGOMONSTER]

check out this thread that may help
http://www.nissanpatrol.com.au/forums/showthread.php?11283-Will-305-65R17-fit-on-a-8-x-17-rim

[Grainger]

Hi guys
just thought i would give you an update -

I actually bought Black Mikey Thompson rims 16" and went with the Cooper ST Maxx 285/75/16. They look great, give me the bit of a lift I was after and believe it or not are actually quieter than the Bridgestone Duellers in 17" I took off !

Thanks for your advice.

Mark