Happy Holidays folks,

I just got some new tires today because a huge bolt got stuck to my tires yesterday. My tires are also past the wear indicators, and I know that nobody would patch up my tires, so I was forced to replace all four. Well, I don't have a lot of money right now, so I went to a discount Rims and Tire store to get whatever I could afford. I ended up getting some cheap tires with the size P225/40/ZR18 on my stock rims. Besides having a larger gap between the tires and my fender, are there any other drawbacks like speedometer and odometer readings? I got all four tires and installed, balanced, and stuff out the door for $333. The tires are Sunny 3800. I only need them to last me through the rainy season and until I have more money to spend on better tires. My thoughts were that any brand new, cheap tires are better and safer than, four balding + one punctured, expensive brand tires, especially in the rain. Anyways, thanks for reading, and happy holidays. Oh, and my question was, what should I be concerned about with my new lower pro tires on stock rims? I won't mess up my suspension, will I?

 

no you will b fine will not damage anything and i don't think just changing from 45 to 40 will effect the speedo or odometer you are fine just have some wheel gap

 

Hi.

Don't worry.

Have a look at the Miata.Net tire / rim size calculator. It's a nifty tool to show you what effect this will have on your speedometer.

http://www.miata.net/garage/tirecalc.html

According to that site, at 60mph, your speedo will be reading 58 mph with the new tires.

As long as all 4 tires are the same size, you will not harm your DSC / Traction control / ABS.

 

Thanks guys for your response. I have searched and seen the tire calc, but for some reason, the java is not working correctly on my browser. I don't want you to think that I have posted without searching, but most of my results were just flames and people saying don't do it. I don't have that luxury right now, and I had to do it. I feel better now knowing that my car won't explode or anything, but I plan on changing them to stock recommended size in about a month or two and then sell these tires cheap to an aftermarket user. I'm scared of ruining my rims or suspension. Right now, I just need some rain traction so I can get to and from work safely. Thanks for the spirit lifter guys. I really appreciate it. Merry Christmas.

 

Hey Silver06,

I just updated my java from sun, and now the tool works fine. Thanks for the link. It's pretty cool. The difference is not as bad as I had thought. My main worry now is rim bending. Since I don't race, I think that I will be fine though. Plus, it's rainy season, and I should be driving and turning corners slower anyway. Oh, and one last thing. I have noticed that once I reach about 40-45 mph, I heard a whirl from the car. Sounds like road noise from the cheap tires. The drive seems fine though.

 

racing should still be fine.

the autocross b-stock champion 4 years running, uses a 245/35/18 tire with his rx8. so.. 225/40 should be fine.

i run 245/40 and i do a lot of spirited driving. and im fine.

 

My traction and steering response seemed to have improved. It's been raining, so I am only basing this off of rainy day driving. I think this has to do more with new treads compared to my old balding ones. I have noticed however that I feel the road more, and that the tires are noisier possibly due to the shorter and stiffer sidewalls. As I accelerate, I start to hear a whirl, almost like intake noise, and it goes away as I slow down. This also depends on the road condition. If it is a newly paved road, then it is pretty quiet. If the road is rough, I can hear the whirl at around 45mph. Sounds like a turbo spooling up. I use to own a turbo Volvo, so I know what the spooling sounds like, and it sounds similar. Kinda annoying because it makes my car cabin sound more ambient, especially at night.

 

I changed from OEM 225/45 18" to Michelin Pilot Sport 2 225/40 18" on stock rims.

No problems what so ever, have driven them one season now.

 

Any change in tire radius WILL affect your speedo. The miata calc. is a great tool.

Keep in mind that the stock speedo is already off by about 3%

 

Thats no problem as long as you stay under 5%.

45 -> 40 is 3,3% and that is no problem, it will only give you a slight but not noticable better acceleration.

Check this link

 

because we can all read swedish...

 

Sorry for that but everyone understand the compare list? I would be glad to help you if someone needs help...

Sorry for my bad /english/swedish I quite drunk, its my first day out of 3 weeks of holiday christmas...



marry christmas and a good year to you all out there!

 

I'm starting to feel a little better about my purchase. Now, I'm no longer concerned about the tire size, but rather, the build quality of my generic brand tires and the workmanship of the discount tire store installer. The more I drive it, the more secure I feel. I still don't 100% fully trust my car yet in a hard corner, but I will slowly build trust after I drive on the tires more.

 

Speedo is off by a couple of MPH from the factory anyway.

 

i could not find any reviews online of the sunny 3800 tire. lol.... anyone else have better luck?

 

Will 245/40/18 fit on the stock rims? I found some tires I really want to get but 245/40 is the only side.

 

Oh sorry, the actual model is Sunny SN3800. The link below is to another forum board for Saturn ION Redlines, but this guy seems happy with them. Good luck finding many reviews for this tire as I have had no luck. The tires work, and that is what I care about right now. It's gonna be raining too much for the next few months anyway.

http://www.redlineforums.com/forums/...-225-45-a.html

 

thats the tire size i run. a lot of people on here do too.

and i meant a professional reivew, not what joe shmoe thinks. haha. he thinks they are better than dunlop sp900s or bf goodrich kdws. hmmm. and he basis his review on a drag launch? uh.. and its not like he was a strip where he could get hard data. so it was all subjective.

 

I knew that you were looking for a professional review, but as I mentioned, I haven't found any. That Joe Shmoe one was the only informative one I could find. I don't think that the tire is popular enough to warrant and time spent for professional reviewers.