Wheel/Tire question for Base Slingshot

I don't normally go out if it's raining, but do ride after the rain has ended or sometimes get caught in rain while I'm out. I've read several criticisms of the Nitto 555 (don't remember if they were about the older 555 or the newer 555 G2 where folks didn't like the 555's (?G2?) performance in rain. The Motivo seems to have a better rep in rain. Anyone have any experience using a Nitto Motivo All-Season tire on their Slingshot?

Quote from MiM

Cool! Thanks guys!

They're from tirerack and were listed as a/s (all season?)...

Where could I find the summer ones? These are $180 for rear and $140 for fronts.

Found a super cheap set of wheels that'll hopefully fit. Thanks to @BKL, I started looking at 5x4.5 wheels too and found some Mickey Thompson rims to give the SS muscle look... We'll see... If not, I'll sell and start again...

Base wheels and tires on Ebay for anybody interested!

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Just watch out for the internal diameter of the wheel. The OE wheels 17 x 10.5 wheel didn't look bad, but the way the wheel was designed (it had a curved interior that reduced overall clearance), it had less internal clearance than the 17" stock Base wheel (whose interior has a flatter design that provides more clearance compared to the SS-style wheel). If you can find a 17" wheel that has the same internal diameter the stock Base wheel has, you should be good to go. I hope to try mounting the stock Base front wheel on the rear tomorrow to check clearances. I'll try to remember to post some pictures.

Okay. Decently comfortable day here just north of Houston, so I removed the stock base rear 18" wheel/tire and mounted my stock base right front 17" wheel. This meant the tire was mounted with its tread facing the wrong way, but I just wanted to compare caliper clearances between the 2 wheels. Looks to me like I had plenty of clearance between the 17" wheel and the rear caliper. Here's a pic showing the 18" wheel's caliper clearance and the 17" wheel's caliper clearance when mounted at the rear -
Given the relatively flat interior wheel surface of the stock base wheels, I'm hoping I can find a similarly shaped 17" x 10.5" (or 11") wheel. While I've known about wheel widening for years, I've never done one before and I think using a wheel that was deigned for a certain width may be a little safer than modifying a narrower wheel. I don't recall having heard about failures of any base model wheels or spokes,but there is always a chance of adding some stress as a result of the widening process, so if I can find a wheel designed for the desired width, I'd rather buy it and matching front wheels, if possible. Plus, the wheel widening company currently has about a 4-6 week backlog.
I do wish I had taken some profile pics from the back to give me a better idea on how a widened wheel using the front wheel would look.

I think I learned more today about the OE Wheels 17x10.5 wheel and why it didn't fit. The JEGS website didn't list the following, but I found it on the OE Wheels website - "Does NOT fit vehicles equipped with upgraded or performance brakes such as Brembo, or specialty models with larger brake calipers including Cobra, Boss, GT500, Shelby etc." The Slingshot has a 298 mm rotor and the caliper sticks out another 38 mm or so. The Cobra mode referred to has a 13" rotor, meaning this wheel had reduced clearance and was more likely designed for a rotor around 11" in diameter.
I've emailed American Muscle about their 10th Anniversary Cobra 17x10.5" wheel which will hopefully clear the Slingshot's brakes. It has +28 mm offset and when combined with the larger tire should place the right side of the wheel in about the same location as stock, with the left side of the tire a little more than 1" to the left. Here's a link to the wheel - Black 10th Anniversary Cobra Style Mustang Wheel - 17x10.5 (94-04 All) - Free Shipping. The AM wheel has 14 spokes in 7 pairs compared to the Base wheel's 16 spokes in 8 pairs, but looks decent comapred the the Base wheels.
Will need to see how it looks before I can make a judgement. Of course, once I mount a tire on the wheel, I can't return the wheel.
Anxiously awaiting American Muscle's response.

Quote from MiM

Well, I am taking a gamble on Mickey Thompson wheels... I've got 18x9 in the front and a 20x10.5 in the rear... Offsets are +22 and +45 so I'm not worried about the rear, but the front is going to be wider and I'm probably not fitting on a trailer... I'll also have to test handling...

So why did I choose these? $150 for all three wheels ($50 a piece! Super special on ebay)! Now the front is black and the back is silver, but getting the rear powder coated or painted to match... Still much cheaper! Wheels are received and in garage...

Just waiting on tires, mounting, and will post pics, but getting recalls done this week hopefully... Also will need the hub centering rings...

Sounds like you pretty much lucked out on the wheels, especially finding the rear in a +45 offset!
The main situation I see with the front tires/wheels will be the +22 offset when combined with the wider wheels/tires will move the outside of your wheels a noticeable distance, I would think. try entering your tire and wheel info into this link for a visual representation of the changes - Online Wheel and Tyre Fitment Calculator. Offset, Tyre Stretch and Speedo Error | Will They Fit
Good luck!

I'm spending way TOO much time on this forum and the old one between waiting for the recall to get done and trying to find an affordable wider rear wheel for when I finally get my turbo installed.

Update - The 10th Anniversary Cobra Style Black 17x10.5 +28 Wheel I ordered from American Muscle ($150 delivered) was delivered yesterday afternoon.
As explained in the first pic, I think the wheel pattern is enough like the Base Slingshot wheel pattern that if I repaint the Slingshot front wheels Gloss Black and also repaint the shiny rim of the AM wheel, I think the two different patterns will work together, allowing me to mount a 315/35R17 Nitto 555 G2 tire on the rear while maintaining compatibility with the speedo and safety systems, while saving over $100 compared to buying a 295/30R18 tire that is the largest tire I can fit on the original Base 18x9.5 wheel.

As the second pic shows, the AM wheel has a significantly larger interior diameter (just under 15.75" for rotor/caliper clearance) than the 17x7 front wheel from my Slingshot (15.25") and much more clearance than the OE Wheel 17x10.5 I originally tried and (barely 1/16" clearance between the caliper and the wheel). The fourth pic shows the clearance around the caliper with the AM Wheel mounted on the rear of my Slingshot.
The only concern about this approach is the fact that the AM wheel is +28 offset compared to the Slingshot rear wheel's +45 offset. This will cause the mounted tire to be a little off-center (see my approximation in the third pic), but I don't anticipate any other problems.
I still haven't ordered the tire as I can not return the wheel once I mount a tire on it. I plan on test-fitting the wheel on my Slingshot later today.

I think I'm going to go ahead and get a tire to try out the AM Wheel.
It looks like I'm going to be ordering some Nitto tires. I was torn between the 555 G2 or the Motivo All Season tires. The 555 G2s are rated 320 AA A and the Motivos are rated 560 A A. Cost per tire is about the same, although the tire replacement certificates seem to cost a little more for the 555 G2s. The Motivos also seem to havebetter wet road performance and a longer life, while the 555 G2s seem to have slightly better dry pavement grip.
At this point, I'm leaning towards the Motivos. Anybody have any experience with either tire?

OK. I finally ordered the Nitto 555 G2 315/35R17 tire from Discount Tire Direct and had it mounted at my local Discount Tire. I put it on the Slingshot a few hours ago and went for a short 15 mile ride. I included a couple of pictures showing the side view of the tire/wheel and a mounted pic of the Nitto on my American Muscle 10th Anniversary Cobra 17 x 10.5" Cobra Wheel. The AM wheel has an offset of 28 mm compared to the Slingshot's 45 mm offset and according to Willtheyfit.com should be offcenter by about 3/5", but it doesn't look bad to me. The wheel was $150 or so and the tire was around $240 with tax and road hazard coverage.
I forgot to mention I also used hub-centric adapter rings with an inside diameter of 66.1 mm to adapt the hub to the AM wheel's hub-bore of 70.3 mm. I got them from JustForWheels.com.
Here's the link to WillTheyFit for a visual comparison of the two tire/wheel combos - Online Wheel and Tyre Fitment Calculator. Offset, Tyre Stretch and Speedo Error | Will They Fit