Rear tire

    I know have 6000 miles on my stock rear tire and I am getting very close to the tags. I have a base model 2016 with the standard rim. Any suggestions on a wider tire and what might be a good replacement ? Any thoughts are appreciated.

    We’ll get there when we get there and not a minute before. 😎

    My general rule of thumb for changing tire sizes is as long as you stay with about 3% of the original circumference you shouldn't affect the nanny controls. As you go over 3%, expect to start seeing the nanny controls illuminate. On my 2015 Base Slingshot, I've kept the stock fronts and gone as high as a Sumitomo HTR Z III 295/30ZR18 ( about .4" shorter than stock) rear, but I only got around 7000 miles on it compared to the 10000 miles I've averaged on 2 Kendas. I also tried a Nankang NS-20 275/35R18 (around 8-9000 miles) and it costs around the same as the Kenda rear tire (maybe even less). The Nankakg NS-20 is considered to have a soft sidewall. I could feel a wiggle during normal straight-line steering wheel play, but in emergency lane changes (right-to left and back) everything felt fine.


    Now that I've got my turbo installed, I reinstalled a NItto 555 G2 315/35R17 (about .3"taller) on an American Muscle 10th Anniversary Cobra Style 17 x 10.5" wheel. The Am wheel looks similar to the Base Slingshot wheel, but only has 14 spokes instead of the Base model's 16 spokes, but I think once all three wheels are repainted, I can get by w/o replacing all 3 wheels. The one drawback to the AM wheel is it only has a 28 mm offset, so the tire centers slightly to the left of the center of the Slingshot, but it still looks OK to me. The AM wheel is currently selling for $150 w/free shipping) and the Nitto 555 G2 315/35R17 tire is around $200, making this combo the cheapest wide rear tire setup for the Slingshot.
    Here's a pic of the Nitto 555 G2 315/35R17 tire on the AM wheel on the rear of my Slingshot showing how it mounts slightly off-center.

    Am offers matching 17 x 9" wheels for the front for $124 each. They are 30 mm offset so the wheels will make the front end about 3" wider, which might cause a problem if trailering the Slingshot.
    TRe Nitto 555 G2 is a Summer UHP tire and doesn't have a treadlife warranty. Nitto also makes the Motivo All-Season UHP tire in the 315/35R17 size which carries a 65000 mile warranty (doesn't apply if tire can't be rotated), but it should hopefully last a while on the Slingshot. If I like the Motivo 215/50R17 tires I'm going to install on the front, I may give the Motivo a try on the rear.

    My general rule of thumb for changing tire sizes is as long as you stay with about 3% of the original circumference you shouldn't affect the nanny controls.


    Awesome reply- thank you! Can you shed some light on the nanny control issues plz?

    We’ll get there when we get there and not a minute before. 😎

    When changing tire sizes, you run the risk of causing the Traction Control, ABS and Stability Control systems to react in an unpredictable manner if the numbers fall outside of the programmed ranges. Actually, it's not so much they react unpredictably, they just tend to shut themselves off if they encounter a problem and I prefer to have them operating without any red lights warning of a problem. That's why I wrote what I did about about trying to stay as close as possible to the original tire dimensions (actually, this relates mainly to the tire diameter). Under 2-3% change, no significant problems have been reported by Slingshot owners as far as I am aware. As 3% is exceeded, problems seem to be more common.
    Some people try to change the front and rear tires proportionally, meaning they try to increase tire sizes about the same front and rear, but as I wrote above, I have changed the rear tire to as big as a 295/30R18 w/o changing anything on the fronts and haven't encountered any problems with handling or triggered any problems with the safety controls. The Nitto 555 G2 315/35R17 tire I referred to above is about .38" taller in diameter (1.5%) compared to the stock rear tire and means an indicated 65 mph will be closer to 66 mph.
    Discount Tire offers a decent Tire Size Calculator to calculate changes in tire sizing (including impact on speedometer accuracy) - Tires and Wheels Near Me | Find a Location | Discount Tire
    Will They Fit allows you to picture the changes in tire size and wheel size/offset - http://www.willtheyfit.com
    Tire and wheel sizing has been the topic of several threads.

    I would like to clarify the information about the nanny controls from running different tire configurations in a search for more traction.


    In the past I went from the stock base model tire size to running 3 base rear wheels all the way around with 265 35 18s up front and a 285 35 18 in the back. This configuration provided me with the best handling ability I have seen.
    After installing a SC and putting out 320 at the rear tire I started my quest for more traction. I intitally installed a 20 inch rim with a 305 30 20 thinking wider is better. What I discovered was the tire was easier to spin because the narrow side wall and no flex in the tire.
    At that point I went back to the 18 x 9.5 rims all the way around. This time I installed a 295 35 18 on the rear that had a sidewall that was almost 5 inches, it measured out at 28.5 inches. Yes with my fronts still being 265 35 18 and 25.3 inches tall the nanny lights came on. Not to worry, I went to the dealership and had them adjust the tire size in the ECU from a base to the SL and the nanny lights went out and never came back on. The only reason they came on was because of the tire size on the rear had changed, not bevause of the ratio front to rear.
    The 295 45 on the back is 12% larger than the 265 35 on the front. This is not a problem with the tire size adjusted in the ECU for a SL.
    Was there a difference with traction? Oh yes, with the pressure set down to 20 I can launch and control the spin. As an added bennifit of the larger circumference, it has the effect of running a bigger gear so the torque band is movoed up abit in the speed range.

    @SoCal, recommend you run a search on this forum about tires. There are several threads that have some good links in them, both where to get good tires, and also some educational pieces and calculators that might help you make a decision.

    Quote from SoCal

    GREAT information and thank you all!

    I am running the same set up as @Slingrazor did originally with the base 18" rear set on all 3 corners and it is by far the best handling I have seen. My next step is to make some changes to coils over and stiffen up the front / soften the rear. That will put me exactly where I want to be. Nice thing is with all 3 wheels the same size I can always have a spare in my trailer.

    The more people I meet

    The more I love my Dog!

    Thoughts?


    I have the 255/30/20 on the rear. This is a 27"OD tire. Rear tire is 1" OD larger than front. I was thinking of taking the rear and moving it to the front, so two 255/30/20's on the front. My plan was to go with a smaller wheel on the back... say 18" and stick with the 1" larger OD mix, which would put the rear tire needed at 28"OD. Found this:
    Mickey Thompson Sportsman S/R Tires 90000000237 - Free Shipping on Orders Over $99 at Summit Racing


    Anyone try and do this before? I know the offsets are just a bit different, but I believe it will fit just fine. Anyone try the Mickey Thompson tire above? I would stick with another 20" wheel on the back, but I'm going boosted with considerably more power, so thought the above tire would be a really good option with an 18" wheel. I've read a lot of the posts on the site, but wanted to run it past the experts!

    :00000436:
    Success is a lousy teacher. It seduces smart people into thinking they can't lose. - Bill Gates

    Quote from SaltyClownNY

    Thoughts?


    I have the 255/30/20 on the rear. This is a 27"OD tire. Rear tire is 1" OD larger than front. I was thinking of taking the rear and moving it to the front, so two 255/30/20's on the front. My plan was to go with a smaller wheel on the back... say 18" and stick with the 1" larger OD mix, which would put the rear tire needed at 28"OD. Found this:
    Mickey Thompson Sportsman S/R Tires 90000000237 - Free Shipping on Orders Over $99 at Summit Racing


    Anyone try and do this before? I know the offsets are just a bit different, but I believe it will fit just fine. Anyone try the Mickey Thompson tire above? I would stick with another 20" wheel on the back, but I'm going boosted with considerably more power, so thought the above tire would be a really good option with an 18" wheel. I've read a lot of the posts on the site, but wanted to run it past the experts!

    You have real curious with this one. I was pulling the trigger on a new Nitro 555 G2 today that is 295 45 18 with almost the sane measurements. I have been using this size of ture for a year and love the grip when run around 23 psi.
    Think I'll order this instead.

    Quote from Slingrazor

    You have real curious with this one. I was pulling the trigger on a new Nitro 555 G2 today that is 295 45 18 with almost the sane measurements. I have been using this size of ture for a year and love the grip when run around 23 psi.Think I'll order this instead.

    Yeah, I looked at the Nitro too. Have been bouncing back and forth between MT, Nitro, and Toyo and trying to decide. This one is a bit more expensive, but I think I like it the best.


    PS... @Slingrazor... so then I'll take it that you don't have any issues with the 28" OD then... or is that what you had to have the dealer tweak in the system?

    :00000436:
    Success is a lousy teacher. It seduces smart people into thinking they can't lose. - Bill Gates

    Edited once, last by SaltyClownNY ().

    Hey, I'll put it on this thread as it's related to what I just posted, but looking for a wheel that matches (somewhat) stock (design wise) that is 18x10 in size? New... used... Not sure what kind of wheels the stocks are...


    Thanks!

    :00000436:
    Success is a lousy teacher. It seduces smart people into thinking they can't lose. - Bill Gates

    Quote from SaltyClownNY

    Yeah, I looked at the Nitro too. Have been bouncing back and forth between MT, Nitro, and Toyo and trying to decide. This one is a bit more expensive, but I think I like it the best.
    PS... @Slingrazor... so then I'll take it that you don't have any issues with the 28" OD then... or is that what you had to have the dealer tweak in the system?

    No I don't have any issues with the 28 inch tire in the rear. Prior to the install I had the base model 18 inch rear on all three and the ecu was setup for the base 18 inch wheels. When I installed the 28 inch tire on the rear I had to have the ecu changed over the the SL 20 inch wheel size. Since you have an SL, you should not have an issue.

    Quote from Slingrazor

    No I don't have any issues with the 28 inch tire in the rear. Prior to the install I had the base model 18 inch rear on all three and the ecu was setup for the base 18 inch wheels. When I installed the 28 inch tire on the rear I had to have the ecu changed over the the SL 20 inch wheel size. Since you have an SL, you should not have an issue.

    Let me know if you get this. My SS isn't going to be on the road for two months as I'm rebuilding it and have the thing in parts everywhere. Hopefully in two months I can test it out ;(

    :00000436:
    Success is a lousy teacher. It seduces smart people into thinking they can't lose. - Bill Gates

    I am going to order the Mickey Thompson and the Nitto 555 G2 today. Both slings need tires. I will be running the MT on mine (320HP) and the NItto on the wife's (NA). For wheels, I am also ordering 6 American Racing 105 M Torque Thrusts in a 18 x 10 with 45 Back Space. Tax returns came in!!!! On the fronts I run Sumitoto HRZ II 275 40 18s. Both slings are flashed for the SL wheels.

    Quote from Slingrazor

    I am going to order the Mickey Thompson and the Nitto 555 G2 today. Both slings need tires. I will be running the MT on mine (320HP) and the NItto on the wife's (NA). For wheels, I am also ordering 6 American Racing 105 M Torque Thrusts in a 18 x 10 with 45 Back Space. Tax returns came in!!!! On the fronts I run Sumitoto HRZ II 275 40 18s. Both slings are flashed for the SL wheels.

    That is a great looking wheel!

    The more people I meet

    The more I love my Dog!