Has anyone driven the new SLR? Or more specifically, put a 305 (or similar) tire on the back?

    The 255 that comes on the SL seems small. Even the base model has a bigger one (by 10mm, but still bigger).


    Since the SLR is coming with a giant tire, I'm wondering how this affects performance. The extra grip would be better for launches, but the extra rotational weight would likely slow it down somewhere around the 2nd-3rd gear mark. I also wonder how it affects general handling.


    Anyone have any opinions or experience?

    I have a 2015 Base and currently run a Sumitomo HTR Z III 295/30R18. I'd like an even larger tire, but they start getting very pricey at the larger sizes.
    Using tire size info from CARiD (Tires Sizes Chart) and Discount Tire's Tire Calculator (Tire Size Calculator & Converter, Tire Size Conversion | Discount Tire), it looks like the bestwider tire for the SLR would be either a 325/30R20 or 335/30R20, which would be running 66.69 mph (+3.5%) or 67.26 mph (+2.6%), respectively, when the speedometer is indicating 65 mph. Personally, I feel the 325/30R20 size would be a better choice since it is a closer match to the speedo settings and less likely to cause problems with the electronic safety systems, but the 335/30R20 should hopefully also work. Discount Tire didn't list anything in the 35/30R20 size in the Houston, TX area, and only listed 2 tires in the 335/30R20 size, Pirelli P Zero at $355 + installation, etc. and the Michelin Pilot Super Sport at $469 + installation, etc. CARiD's prices were similarly expensive.

    Quote from chad warren

    I don't care how big it is still a crap ass Kendra. If your going wider go aftermarket.

    That's fair. But even going 255 Kendra to 305 Kendra would be an excellent comparison.


    A wider tire would obviously increase surface area, but would reduce weight per square inch and increase rolling resistance and rotational weight. So I'm wondering where the sweet spot is for these machines.

    Personally, I prefer the widest tire I can AFFORD to use on the rear. The Sumitomo I referenced above is the widest, least expensive high performance tire I could find and I can still spin it with my non-turbo'd Slingshot. It offers better traction than the stock Kenda, but if I don't get enough tread-life out of it, at twice the cost of the stock Kenda, I may look for a different, less expensive tire next time. I'm still running my original Kendas on the front at 26K+ miles and have no complaints about them. The Kenda on the rear, though, just spins way too easily.
    Wider tires will result in a lower weight per square inch and increase the chance of spinning in rain and hydroplaning, but I only ride in rain if it rains while I'm already out. If rain is forecast, I generally don't go out unless the likelihood is relatively low (15-25% or less). The extra mass of a larger tire may well cause some delay in how quickly it will spin up during acceleration, but as far as I am concerned, it's a non-factor unless racing

    I had an SLR for a day here while mine was in the shop. It's sharp enough I suppose, but I love my Black Pearl.


    As for that rear tire, that thing looks huge on there in comparison to mine. Hydroplaning would be an issue for me. Plus, I had to go down a gravel road for a half mile. I've done it a lot on mine and while I know the feel of it on the gravel, I felt that this thing was on marbles! That rear tire does not like gravel. She's a pavement baby.

    Would like to go a little wider but will likely stick with my stock wheels for now. As for the Kenda's, I agree completely with BKL. The fronts are wearing really good and with all the tires I buy every year from street to snow for all my vehicles and toys I have a hard time spending extra money on wear items unless there is a specific reason for it. If I had a tendency for more track days its a no brainer to upgrade the rubber but I just don't have enough time to get to the track currently.


    Same opinion as most on the Kenda out back but I have learned to control the spin on takeoff for those times I actually need to. In fact, red light raced a couple different vehicles over the weekend including a Harley fully decked out in screaming eagle everything. He had a slight disadvantage with his passenger out back but he wanted to go anyway. I know I scared the living shit out of both him and his passenger when I hit redline in both second and third gears with the Alpha variable in the fully open position. I was already out front but both sets of eyeballs were as big as saucers. Not sure either had heard a non-stock Sling from a few feet away. Probably pissed that a $20K Polaris sling was louder and faster than his highly modified hog.......