Comparo: 225/40 vs. 215/45

[Matt'sSpeed6]

Can anyone comment on the difference and similarities between these two sizes? I would expect better traction but worse ride on the 225/40. Naturally, there are more tire choices at the 225/40 size. And therefore, better prices.

What changes can I expect from the car?

Pictures of the 225/40 would be appreciated!!

Thanks everyone.

Matt

 

[wannabe]

your on Miata.net, and haven't used their calculator?

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

2.1% difference. rule of thumb is less than 4% your fine.

 

[Matt'sSpeed6]

I realize there is a marginal difference (and Yes, I do know about the size calculator). I was really looking for real-world opinions based upon experience.

Is there any change in ride?
Is there any problems mounting to the rim?
Is there a fitment problem on the car?
Does anyone regret a change in this size?

I have made size changes in the past and have regrettet my decisions after the tires were on. So I really was just looking for some opinions.

Thanks!

Matt

 

[TX Speed 6]

I have 225 45 and honestly can't tell any difference (besides as you mentioned the variety and prices of tires). I really think you will be satisfied. They test fitted 225 40 for me at discount but they looked kind of stretched, so I didn't like it. Thats why I went with 45. I got my RX8 rims now, so it paid off to go to 225 so I could use the same tires still too.

So to answer in your format:

1. Not that I could tell but you might others might be more sensitive to it than me
2. None
3. No, I'm lowered on RPM springs on RX8 rims, no fitment issues at all
4. Not at all

 

[Matt'sSpeed6]

I have 225 45 and honestly can't tell any difference (besides as you mentioned the variety and prices of tires). I really think you will be satisfied. They test fitted 225 40 for me at discount but they looked kind of stretched, so I didn't like it.

What do you mean by "stretched"? Tires pressing out past the rims?

Thanks.

 

[MX5RACER]

This is stretched:

 

[Tinstar]

I went with the 245 Eagle GT's on my MS6.

Similar but less grip than the stock Potenza 050.

Smoother ride through a squishier sidewall and less psi. 38 psi on the original rubber, 36 psi in the Eagle GT's.

Much better grip in the rain, easily drove in the light snow/ice in central OK.

Car is quieter, again through the softer sidewall and soaks up the sharp edge bumps better.

Stock rims/ride height so fenders look full now.

I never liked looking at the 6 from the back becuase the original tires looked too skinny. Now it looks just fine.

No change in fuel economy. I track mpg every tank.

Slightly more steering input heading to the apex. Slightly less steering input accelerating away from the apex. Car is slightly more sensitive to f/r weight transfer in the corner.

Tire appeares to be too close to the fender lip especially on the rear however no rubbing anywhere at all through full suspension movement front and rear.

The clearance on the rear is close enough that the same size tire in a different brand could rub.

Here's a pic with the Eagle GT's.

 

[Super Shredder]

what tire size is more agressive yet cheaper? is there a better size of 18'' wheels that outperforms the potenzas in this rediculous size pattern? i remember last year i tried to price tires at costco all they had were run flats at 330 dollars per tire. LOL. i've had potenzas, both kuhmos, and now on pzero neros all weather AAA tread (pretty fantastic)

 

[Super Shredder]

+20hp for Bull Terrier boost guage. one bark means 18psi two barks means spiking too high!

 

[m4tic]

im on 225/40s

 

[Super Shredder]

 

[SwampAss]

225/40s ride a bit stiffer than do the 215/45s but for the money difference, it's worth it. They are also slightly smaller in diameter. Lower gearing = quicker take off! Even if it's only slightly.

 

[Silver Ecstasy]

My next tire size was hopefully going to be 225/45 just for added wheel protection. A couple guys run 225/40 on stock rims no problem and their cars feel fine.

There was a guy who said our 18x7's weren't meant to be fitted with 225/40's that they were an inappropriate size..?

 

[Matt'sSpeed6]

Sorry everyone, but I gotta show Shredd my dogs.




Penny = White & Deaf, Pony = Brown

 

[Matt'sSpeed6]

im on 225/40s

m4tic:

Looks good. Are you satisfied with them? What brand/model did you go go with?

I am leaning towards the BS RE760. I am a huge BS fan. Pulled Dunlops off of my 4Runner and put BFG A/T on. Hated them. Sold them and and put on (and should have put on in the first place) BS Dueller A/T REVOs. Put BS on my Monte Carlo (when I had it) after the GY Eagles. So much better. Made the mistake of putting GY F1 GSD3s on my Miata.
One more thing: did you lower the car after putting the 225s on? Or how did it look with the stock height? Probably not too much difference, I would assume.


M

 

[m4tic]

i have kumho ecsta ast's, they're a hit with me so far. i dropped the car after the tires, i dont have pics at stock height ( i cant stand looking at the pics i do have at stock height, ugh) also i went with a lower profile because im planning to swap in some 18x8.5 wheels, and stretch just a tad.

 

[Super Shredder]

so the perfect safe fitment would be 18x8 225/45?

 

[Japan8]

I've got a set of winter tires in 225/40 and I don't recommend them. During a recent drive from MI to FL I checked my speedo against my GPS and yeah... at 60mph the % different isn't a big deal, but by 80mpg there is a big difference. My speedo read 80mph, but my GPS said about 71mph. And of course this gap is only going to get worse as you go faster. So go 225/45 instead (ride quality is better too).

 

[Matt'sSpeed6]

I found that BS now makes a RE760 in stock size. That is probably how I am going to go. The speedo difference also means odometer difference. So for every 5000 miles your odo say, you have only travelled 4600 miles.

M

 

[bxs144]

I just had some Falken RT-615 225/40 ($125) mounted on the stock rims, not enough driving on them yet, but will be going to an autox on 3-29.