Hey guys, I read a bunch on here but never post. I have been getting mixed messages so figured I'd post up. I'm looking to get a set of 19's for the q70. I like the staggered look/feel (tell me if I'm drunk). Sites suggest 19x8.5 and 19x10 (front/back). Tire sizes are being suggested differently on each site. For looks I'm thinking I'd want 245/40/19 with 275/35/19 but I'm not seeing that suggested on any of the sites. I'm seeing 245/45/19 with 275/40/19 though...I even saw 35/30 suggested by Wheelfire, for example, and they don't let you change it online.

Any reason I couldn't do what I was thinking? I will be lowering it on BC coilovers before putting on the new setup in the spring.

PS: I love the 20's but seeing 35/30 as the suggested options for my car scares me a bit living in New England with our horrible roads. I'll be getting Niche/TSW or similar and Toyo/Nitto level quality in case that matters.

Thanks for your thoughts!

Welcome to the forum...

I see that your car shows as a AWD Q70, which most people will tell you running staggered wheels is a no no for. I ran staggered on my AWD FX45 with no issues but like I said, most will tell you not to do it..

As for the tire sizes, 245/45/19 and 275/40/19 will be the ones that keep your speedo closest to reading accurately since the stock OEM 20's are 245/40/20. In theory if you ran staggered 20's, you could do 40/35 series tires.

I hope this helps.

If you run staggered you just need to be DAMN SURE your rolling diameter is 100% otherwise you may or may not (more likely may) throw off the AWD computer and cause it issues.

Welcome to the forum. I live in Upstate NY and our roads are similar and I'm on 20's...it's not that bad.

Don is NJ and IMO, after living in NJ this summer, their roads are crap too hahah. Go big or go home .

DoN_BLaZe34 wrote:I see that your car shows as a AWD Q70, which most people will tell you running staggered wheels is a no no for. I ran staggered on my AWD FX45 with no issues but like I said, most will tell you not to do it.

Here I am; don't do it. Some good reading on the subject HERE.

What about a different offset in the rear with the same width and tire size? It will sit wider in the rear and still have the same contact patch and roll count (diameter/circumference). Just an idea.

Don't know if you're willing to go with 35/30 series rubber considering the quality of NE's roads. I'm running 245/35/20 and 285/30/20 on 20x8.5 and 20x10.0. Circumference is identical front/rear although slightly smaller than the OEM sport package.

IlyaKol wrote:If you run staggered you just need to be DAMN SURE your rolling diameter is 100% otherwise you may or may not (more likely may) throw off the AWD computer and cause it issues.

Indeed, it is best not to risk it at all!

The problem with trying to match the rolling diameters between staggered front and rear axles, is that this is not a simple static or calculated measurement. Depending on the tire brand/model/size, the sidewall flex, the cross-section width, etc., the effective rolling diameter is not a simple calculation and may well change as the car moves.

Many "tire calculator" sites try to get you close, so that people can change tires using different aspect ratios, larger wheel diameters, etc. But these calculators are generally too simplistic. They are based on physical tire and wheel dimensions and cannot take the actual tire model (sidewall stiffness, cross-section, etc.) into account at all.

For example, in the Tire Rack specs, even tires with identical sizes from different manufacturers (and even within a single manufacturer lineup) can have different rolling diameters. The correct measure of rolling diameter is the "revolutions per mile" value in the specs - this will come closest.

However, the problem is that mismatches can lead to handling problems and/or increased wear and tear on the AWD system. Basically, to avoid problems with the Nissan/Infiniti AWD system, the tires and wheels must be identical on all axles - this is stated in a number of places in the User Guides and Service Manual ... in bold print.

Note that I did not say "stick with OEM" or "never change the wheel diameter" ... merely that the tires and wheels must be "identical"! Also, measuring and keeping the tires inflated to the same amount (relatively speaking) is also important ... measure often on AWD cars!

By the way, one other common practice of using wider wheels or tires - to make the "tires/wheels flush" is the supposed reason - must also be done with care. In general, when using wider wheels, it is best to also change the offset of the wheel correspondingly - as long as it still fits. This makes the suspension line through the tire contact patch on the ground remain unchanged. Then, as the tire moves up and down, the suspension moves in the correct arc as designed by the automotive engineer. This provides the optimal designed handling and reduces the tendency for unusual tire inner/outer edge wear, etc.

Same issue arises with spacers that only move the wheel outwards without increasing the wheel width to ensure that the contact patch remains in the same relative location compared to the suspension design.

Z

Debonair wrote:

DoN_BLaZe34 wrote:I see that your car shows as a AWD Q70, which most people will tell you running staggered wheels is a no no for. I ran staggered on my AWD FX45 with no issues but like I said, most will tell you not to do it.

Here I am; don't do it. Some good reading on the subject HERE.

A good reference. Thanks!

Debonair wrote:What about a different offset in the rear with the same width and tire size? It will sit wider in the rear and still have the same contact patch and roll count (diameter/circumference). Just an idea.

Still has some problems - albeit perhaps not as bad as different sizes ... as long as spacers are not used, of course, to achieve this offset change!. You could end up with suspension moving through different motion (depending on the car), with corresponding altered handling behavior.

AWD cars are limiting in this regard ... I recommend just being happy with the other advantages of owning an AWD car (traction in slippery conditions, etc.)!

Obviously running staggered is at your own discretion but i had no issues running on staggered wheels on my 2007 G35x. I sold my wheels and tires to a gentleman with a 2009 M35x and he said he never experienced any issues.

I really like to use this website to compare the front wheel/tire setup vs the rear (assuming you are running staggered):

http://www.rimsntires.com/specspro.jsp

Just like szh commented every tire manufactures can potentially have different rolling diameters. The "245/45/19 with 275/40/19" seems to be a better combination because the wheel/tire calculator I posted above shows that they are the same rolling tire diameter.

I use 20's on mine in New York, it makes for dicey driving sometimes lol. Get high quality wheels and enjoy, 19s look really small on this car imho. I understand not wanting to damage the car, but I haven't had any issues using staggered with AWD. Changing the offsets etc as SZH said does affect ultimate handling but if you're just driving around at normal speeds there are no issues that I can forsee. Like people have already stated get the same overall height tires and enjoy