Tire Questions: Need Help

[SHOkid13]

I will be getting a set of tires and rims before the convention this year. I think I have decided on the BFG g-Force T/A KDW-2 tires in 235/40-17. I have been running the ES100s on my slicers with joy, but from what I can tell, the KDW is a better tire and commands more praise than the ES100s. Plus I should get more than 15K miles out of the KDWs. Comments welcome on tire choice.

The rim I like is on TireRack.com, the Kazera KZ-V 17x7. It is only 18.1 lbs and has an offset of +40mm, and cost only $134/ea. All is gravy, but the tire is rated for a rim of 8-9.5".

Question is: Can I go with this setup, or will I decrease the performance of the tires by squeezing them into the 7" rim?

If I downsize to the 225/45-17 size, the recomended rim size is down to only 7-8.5". And I would save ~$80 on the tires.

Is there going to be a huge difference in the two sizes?

Thanks!!

 

[K-Dawg]

I have the KZ-Vs on my car, and I'm pretty happy with them for the price. I just wish they were wider.

I have 215/50/17 ES100s on them. Next time, I'll probably get a 225/45/17. 225 is the largest section width I'd go with on a 17x7.

 

[NotSoSlowSHO]

Simple rule of thumb for wheels and tires:

Find the widest wheels your car can use, and mount the most narrow tires you can.

I would have to say that a tire meant for a 8"+ wheel has no business being on a 7" wheel. Serious tire squat, and those side walls will wander.

 

[jedhead]

OZ Racing Superleggra is one inch wider and one pound less, but do cost more. I would stick to 225 width with the 7" wide wheel. There are a good selection of 225/45-17's. You will loose some turn-in sharpness and precision with the 235 on 7" wide wheel. 225/45-17 will work fine. They are shorter than stock so your speedo will read fast, however you will have just a little bit better acceleration because your overall final drive ratio is shorter.

Bob

 

[Yamaha V6]

I have VERY successfully used 235/45-17 tires on a 7" wheel (it was much better on a 7.5" wheel though). Now, you have a smaller profile, so the sidewall will have to come in on a steeper angle for the 7" wheel.

FWIW, I have also heard of 245/45-17's on a 7" wheel, but that's a little hairy in my book. I would not go to a 40-series tire on the SHO unless you're in 18's, personally.

 

[Dan H]

I agree with Fred,

Go with a 225/45 or 235/45 on a 7", 235/45 or 245/45 on a 7.5-8".

I have 235/45 AVS Sports on my 17" Konig rims and like them very much. I think the rim width is 7.5, it might be 8".

 

[DDakRT]

I have 235/45/17 on my 7" wide Enkies with no problem.

The KDW-2 (the same ones on the SRT-4 from factory right?) grip great, but will lose their grip when it's heated up, and I'm not sure about their tread life.

The KDWS all seasons though are awsome, grips great (not as much as the Summer KDW obviously) and last forever.

 

[K-Dawg]

I would think that the manufacturers recommend at 7.5+ rim width on a 235/45/17 for a reason.

Generally, a narrower tire on a wider rim is better than a wider tire on a narrow rim.

 

[SHOkid13]

Simple rule of thumb for wheels and tires:

Find the widest wheels your car can use, and mount the most narrow tires you can.

I would have to say that a tire meant for a 8"+ wheel has no business being on a 7" wheel. Serious tire squat, and those side walls will wander.

Hmmmm. You were supposed to tell me that it would be just fine to do that. lol

Thanks! I'll go with the 225s

 

[SHOkid13]

I would think that the manufacturers recommend at 7.5+ rim width on a 235/45/17 for a reason.

Generally, a narrower tire on a wider rim is better than a wider tire on a narrow rim.

True. But manufactures don't recomend speeding either. And they give us high HP cars to play with... so??

Good points. Taken well. I'll go with the 225/45 YR17 on the 17x7 wheel. That size is rated for 7-8.5" wheels.

 

[SHOkid13]

Just a comment/question: Why is a narrow tire/wide wheel better than the inverse?

Does it have to do with tire roll and wandering?

 

[SHOkid13]

I have VERY successfully used 235/45-17 tires on a 7" wheel (it was much better on a 7.5" wheel though).

I would not go to a 40-series tire on the SHO unless you're in 18's, personally.

I would personally rather stay with a 45 or 50 also, but they don't make it in the KDW2.

Which tires were the 235/45-17s that you used "VERY successuflly"?

How much difference is there going to be going to a wider rim? I am trying to keep it under $1200, but if it is a huge difference, I may want to do more for the performance gain. I don't have a lot of power on my SHO and I am not planning on having that much on this car (just the bolt-ons and tuning), so I don't need to hold 300hp to the ground. But, I need to stick to the road really good too. I track my car and have the need for cornering speed.

 

[SHOkid13]

OZ Racing Superleggra is one inch wider and one pound less, but do cost more. I would stick to 225 width with the 7" wide wheel. There are a good selection of 225/45-17's. You will loose some turn-in sharpness and precision with the 235 on 7" wide wheel. 225/45-17 will work fine. They are shorter than stock so your speedo will read fast, however you will have just a little bit better acceleration because your overall final drive ratio is shorter.

Bob

I am used to the speedo being a tad bit fast with my current tires, and I like the added take off "edge".

I like the OZ wheels, but I can't afford to pay $146 more per wheel. That's a little above my budget for now... (they are .4lbs heavier according to TireRack.com)

 

[NotSoSlowSHO]

Which tires were the 235/45-17s that you used "VERY successuflly"?

Ill answer that one for Fred, as his team dynamics 17x7 and 235/45-17 TOYO setup should be arriving to my door step in a big brown truck today.

They are Toyo Proxes T1-S tires

 

[Yamaha V6]

Ok Kenny, you can wipe yourself now...

I had 235/45-17 BFG G-Force KDW tires on there first, same size. Those tires were also on my old 17x7.5 Team Dynamics wheels and were a bit more stable under extreme cornering.

I run 225/55-16 tires on my 16x6 slicers (Blizzaks, bulges), and 16x7 BBS wheels (again, BFG KDW, less bulge with the 7" wheel).

Maybe Kenny can snap a quick pic showing the wheel / sidewall / tread area on an angle or something while they're off the car?

 

[K-Dawg]

True. But manufactures don't recomend speeding either. And they give us high HP cars to play with... so??

Good points. Taken well. I'll go with the 225/45 YR17 on the 17x7 wheel. That size is rated for 7-8.5" wheels.

Tire manufacturers make tires that are designed for high speed use. That's what the speed ratings are for. They only recommend against speeding with non-performance tires. I don't think that's the point you were trying to make though.

You're correct on the wide tire/narrow rim. A wide rim will spread the tire out across the pavement, allowing for more precise handling. You may also experience more middle (center) tire wear with a wide tire on a narrow rim.

BTW, here's the KZ-Vs on my car with 215/50/17s:

 

[NotSoSlowSHO]

Maybe Kenny can snap a quick pic showing the wheel / sidewall / tread area on an angle or something while they're off the car?

Ill do that this evening.
AFTER dinner. :wave:

 

[NotSoSlowSHO]

mmmm... BBQ'd salmon

Here are a couple of pics:

235/45-17 tires on 17x7 TD wheels

 

[SHOkid13]

mmmm... BBQ'd salmon

Here are a couple of pics:

235/45-17 tires on 17x7 TD wheels

Doesn't look like they hang over too far... Could that just be that brand tho...

Thanks for the pics!

 

[SHOkid13]

Tire manufacturers make tires that are designed for high speed use. That's what the speed ratings are for. They only recommend against speeding with non-performance tires. I don't think that's the point you were trying to make though.

No, you're right, I was trying to be a smart @$$.

My main thing is to get a good fitting, good performing tire/wheel combo. I had always been under the impression that the wider the better, as long as it would fit. But, now I see the light! Thanks for the help.

And, nice car! Where did you get the wing?