: Tire size



mrstang94
04-08-07, 08:29 AM
I have an 04 srx v8. and was wondering does any one know why the use the (2) different tire sizes from front to back I would like to put all the same size on it and go wider for and be able to rotate them for better wear has anyone done this and do you know how wide I could go.

Thanks

b4z
04-08-07, 08:50 AM
You can go 255 all around but I didn't have any abnormal wear prrobs with my originals.
just replaced them with 37K miles on the RSA's. Could have gone another 4-5K but with the wife driving I wanted some more tread for raindriving.

Northern SRX
04-08-07, 09:56 AM
Yup, you can go either 235 or 255 all around with no problems. I think most here have gone 255 when they've done the swap and that should increase your road grip all around in dry conditions - great for keeping the rear from breaking free under hard acceleration but a wider tire on the front, being grippier than a narrower one, might introduce more resistance to steering input. Keep in mind that the V8 SRX was computer-modeled and the staggered set-up was considered to be the ideal combination of acceleration at-launch, handling, and moderately lower top-end drag.

I guess, in the final analysis, it all depends on what you want your SRX to be - I personally consider it to be a tall wagon with strongly sporty characteristics. That is particularly so when equipped - as mine is - with the N* V8 and MRC. 'twould be even more so if it were RWD rather than AWD. That being said, the performance differences between staggered and uniformity are modest - mostly due to the sheer weight of the SRX. So, the switch to 255s up front ends up being, for most drivers, negligible for 90%+ of the driving that we do.

Since I find the front road grip with the 235/255 set-up to be quite good (mine is AWD), I don't want to fool around with it and perhaps introduce more oversteer. So, I'll live with the PITA of not being able to rotate the tires. I personally think the ideal set-up would be the stock staggered set-up with grippier tires in the summer and 235 snows all around in the winter.

Your mileage may vary...

mrstang94
04-08-07, 12:36 PM
mine is awd n* and mrc also just wanted a cool wide stance "look" but if you seem to think it will affect handling and computer aspects think we should leave well enough alone. The tread in the center is more than ample just noticing the sides wearing a bit from fast cornering. Thanks for the input. Ill put the money for now into corsa exhaust.

z32drifter
04-10-07, 08:42 PM
When the time comes I'll be going with the 255s all around, I'll also move to a proper summer performance tire. Hopefully the selection of 6x115 wheels will improve in the future a 9" front and 10" rear could be an intresting combo.

b4z
04-11-07, 07:04 AM
Yeah, the 6 bolt thing will continue to hurt us when it comes to wheel choices. It was completely unnecessary on both the the CTS-V and SRX.

Dinger77
04-11-07, 11:39 AM
You can put a 6x4.5 bolt pattern on the srx as long as it is hub centric. a 6x4.5 = 6x114.3 which is 7 tenths of a millimeter off the factory pattern. I have a set on mine, an I have had no problems what so ever. This will open up a wider range of wheels for you.

b4z
04-11-07, 02:05 PM
Dinger77,

How about some pics?

Northern SRX
04-13-07, 04:53 AM
mine is awd n* and mrc also just wanted a cool wide stance "look" but if you seem to think it will affect handling and computer aspects think we should leave well enough alone. The tread in the center is more than ample just noticing the sides wearing a bit from fast cornering. Thanks for the input. Ill put the money for now into corsa exhaust.

I actually believe that 90% of SRX drivers wouldn't notice the difference as so much depends on the conditions of your tire, how fanatical you are about keeping the inflated and the speed and angle at which you like to take sharper curves... :rolleyes:

While the SRX is up to the task of driving "sportily", I don't think most people routinely drive aggressively through sharper twisties - so, I suspect that a tad more oversteer at the limits is not going to bother most people . If you put super grippy tires on the front and then really drove it, I'm guessing you'd notice the difference with the wider tire. Of course, you'd also be putting a little more stress on your suspension components (in theory) but I do not know what they're engineered to support over the long haul so I cannot say if there's really anything to worry about there. It's out of this fear that I've always felt more comfortable widening the rears as opposed to the front tires.

Again, though, YMMV...

b4z
04-13-07, 11:34 AM
Keep in mind that if you put grippier tires on a car it actually increases body roll because the limits are higher and the suspension is being compressed more.
I took off the crappy OEM tires on my GTO and put on BFG kdw NTs and it turns in faster, and I can accelerate harder without wheelspin but in steady state cornering I have more body roll.

z32drifter
04-14-07, 07:04 PM
considering I've stiffed 275s under the front of this car.
http://i23.photobucket.com/albums/b359/z32drifter/sig.jpg
and run 255s on my daily driver (sometimes racer)
http://i23.photobucket.com/albums/b359/z32drifter/gnv_autox20339.jpg

I feel silly with 235s on the front of the SRX

TSS
04-15-07, 07:33 AM
As you know, the Z32TT came with staggered wheels too.

z32drifter
04-15-07, 10:06 PM
As you know, the Z32TT came with staggered wheels too.
I run a staggered setup on the Z for the street, 255f 275r. It helps to offset my track alignment, the slide in the picture happened at 60-70mph. That would not be fun on the street, so my staggered setup causes understeer at the limit. Even with all my suspension mods I can't dial out the understeer of the staggered setup on the track, so I went with 275s front and rear.

The mods on the SRX have started already, cleaned it up today and started working on a minor grill mod. (wife is not into the V type grill :( )
http://i23.photobucket.com/albums/b359/z32drifter/Picture040.jpg

Northern SRX
04-16-07, 07:12 AM
Cool - subtle mod but cool all the same.

Your comments about the Z's understeer are interesting and it's kinda my point about the SRX - if you don't steer it aggressively in the twisties, I don't think there's an issue moving to 255s all around, even on an AWD set-up. If you do, you'll probably be imparting more oversteer with the 255s up front but 95% of drivers wouldn't even notice the difference. At the end of the day - as sporty and capable as it is - the SRX is still a tall wagon and a staggered set-up is probably of little import to the majority of drivers. I'm leaving it as because I like the current handling and am inclined to occasionally toss it around...

TSS
04-16-07, 07:36 AM
I run a staggered setup on the Z for the street, 255f 275r.

I never messed with the stock sizes on my TT. I am not messing with them on the SRX either. TT, because of the four wheel steering. SRX, because it is leased! If it was not leased, I would likely get 255 all around.

b4z
04-17-07, 07:18 AM
TSS,

I finally bought a set of wheels and tires for my leased GTO. I had never put any money into my leased cars before but I figured I would have to buy a set of tires during the lease period anyway so why not have some fun.
Plus I can sell them for 50 cents on the dollar when the car is turned in.

TSS
04-17-07, 07:33 AM
It is food for thought. However, I only have a 27 month lease and will likely only have 23 or 24K on the vehicle when i turn it in - I think I can get away without replacing tires...hopefully....with non aggressive driving.....

z32drifter
04-17-07, 11:33 AM
It is food for thought. However, I only have a 27 month lease and will likely only have 23 or 24K on the vehicle when i turn it in - I think I can get away without replacing tires...hopefully....with non aggressive driving.....

Depends on the tires. My 05 has the Michelin pilots on it and they are still in good condition at 23k (good enough to pass the CPO test) The P6s on our SAAB 9-3 were junk at 24k I had to replace them before the lease was up.

TSS
04-17-07, 08:15 PM
I have the V8, so I have the Pilots.