225 45 R18 v 215 45 R18

MetzgerMeister

So I'm getting new tyres for the MPS soon. On the plate, it says to use 215 45 R18 93Ys all round. However, since there's a much wider (and a bit cheaper) range of 225 45 R18 91Ws, many owners choose this option instead without any problems.

My question is this: since I'm not fully up on the pros and cons of different tyres, which should I go for? I will be getting Bridgestone Potenza RE050s.

W.Shakes-Beer

To be honest, I wouldn't imagine you'd notice or even feel the 10 ml of difference. Most cars you could go even 20 ml without any real differences.

If the price was good on the 225's I'd go for them as there really isn't much in it.

MetzgerMeister

I'm not too pushed about feeling a difference to be honest. Just wondering which would be a better option regarding the car's performance if you get me.

I have a thing for sticking to manufacture guidlines, spec etc. whether it's silly or not. The 225s are about €10 cheaper each also. Not too fussed about that.

The 215s have a higher speed rating so would that make a difference? Not that I'm ever going to be going that speed of course :rolleyes:

b318isp

There will be a slight increase in the height of your sidewalls. This will have a minor effect in gearing (longer), make your speedo read a little lower at the same speed, may soften the feel of the car slightly and may cause fouling on body work.

Overall, I doubt if you would notice any difference.

W.Shakes-Beer

b318isp wrote: »

There will be a slight increase in the height of your sidewalls. This will have a minor effect in gearing (longer), make your speedo read a little lower at the same speed, may soften the feel of the car slightly and may cause fouling on body work.

Overall, I doubt if you would notice any difference.

The sidewalls would still be 45 regardless, the difference will be the width I'd imagine.

Nissan doctor

W.Shakes-Beer wrote: »

The sidewalls would still be 45 regardless, the difference will be the width I'd imagine.

The sidewall measurment on a tyre is a % of the width of the tyre.

So 45% of 215 is a different height to 45% of 225.

MetzgerMeister

I also want to lower the car in the future and don't want the tyres rubbing the arches. The fact that they are both 45 wouldn't make a difference.

Another question, if the alloys are made to fit 215s, how do 225s fit without the chance of popping off? Are they just inflated less?

Personally, I would rather go for the 215s just so I can have peace of mind regarding gearing, proper speedo readout etc. but if there's any advantages to using 225s (apart from being cheaper) I'd love to hear them!

I've just realised that it makes no difference regarding the wider range of 225s since I will only be getting the Potenzas.

Nissan doctor

einheisserschre wrote: »

I also want to lower the car in the future and don't want the tyres rubbing the arches. The fact that they are both 45 wouldn't make a difference.

Another question, if the alloys are made to fit 215s, how do 225s fit without the chance of popping off? Are they just inflated less?

Your only talking 5mm wider each side of the rim so there would be no issues with fitting them to the wheel.

Unless you are going for the stance look then lowering the car should't pose any issues either as long as the wheels are the correct fitment and offset(or are you still running the original wheels?)

einheisserschre

einheisserschre wrote: »

I also want to lower the car in the future and don't want the tyres rubbing the arches. The fact that they are both 45 wouldn't make a difference............

There is obviously a greater chance of 225 45 18s rubbing when l;owered than 215 45 18, the 225 45 18s will be wider and the diameter is more due to the extra profile.

Speed wise I can't see an issue, 225 45 18s were standard on e46 M3s iirc.

Would you have a peak at 225 40 18s? The profile is a better match, I think 225 40 18s are cheaper than 225 45 18s too.

MetzgerMeister

Nissan doctor wrote: »

Your only talking 5mm wider each side of the rim so there would be no issues with fitting them to the wheel.

Unless you are going for the stance look then lowering the car should't pose any issues either as long as the wheels are the correct fitment and offset(or are you still running the original wheels?)

So really, it's as much as makes no difference?

I'm going for the stance look along with wanting the car to handle better. Yes, original wheels.

here.from.day.1

W.Shakes-Beer wrote: »

The sidewalls would still be 45 regardless, the difference will be the width I'd imagine.

The 45 is a % of the width. A 10mm difference is going to be totally unnoticeable.

here.from.day.1

here.from.day.1 wrote: »

The 45 is a % of the width. A 10mm difference is going to be totally unnoticeable.

In fairness that 10 mm (more like 11mm anyway I think) will be an overall diameter of 22mm, guts of an inch.

When I bought my ZT it had 225 40 18s on it, they were close to the 1.6mm so I wasn't bothered, there should have been 225 45 18s on it, on a low car it made a difference to be honest, on speed bumps the engine guard was scraping on some more aggressive ones on the smaller tyres.

MetzgerMeister

RoverJames wrote: »

There is obviously a greater chance of 225 45 18s rubbing when l;owered than 215 45 18, the 225 45 18s will be wider and the diameter is more due to the extra profile.

Speed wise I can't see an issue, 225 45 18s were standard on e46 M3s iirc.

Would you have a peak at 225 40 18s? The profile is a better match, I think 225 40 18s are cheaper than 225 45 18s too.

What I really need to get my head around is what Nissan Doc said regarding the 45 being a percentage of the 225/215 rather than it being a definitive number.

The 40s are cheaper but would they not make the car feel even more wobbly?

stealthyspeeder

I went with the 225's on my 3 MPS, were a lot more than a 10er cheaper up north, I think they were about 35% cheaper all round if I remember correctly. Also the contact patch with the ground will be that little bit better with 225's (not a lot but given its pretty small anyway...)

I did a trackday on 225's so if there was any danger of them popping off it would have happened then as I was thrashing it and often asking for more grip than the tyres could give in the corners!

Gophur

Your speedometer will read 1.38% less, if you move from 215 to 225 tyres.

Your mileometer will also read less by the same amount.

http://www.tyresave.co.uk/tyresize.html

einheisserschre

einheisserschre wrote: »

What I really need to get my head around is what Nissan Doc said regarding the 45 being a percentage of the 225/215 rather than it being a definitive number.

The 40s are cheaper but would they not make the car feel even more wobbly?

It's conceptually not too bad

225 45 18

225 is the width in mm

45 is the profile, which is a %, it's 45% of 225 (the width)

18 is the rim size

I would reckon the 40s on the 225 width would make the ride stiffer compared to 225 45s, less profile, less air, less rubber

MetzgerMeister

stealthyspeeder wrote: »

I went with the 225's on my 3 MPS, were a lot more than a 10er cheaper up north, I think they were about 35% cheaper all round if I remember correctly. Also the contact patch with the ground will be that little bit better with 225's (not a lot but given its pretty small anyway...)

I did a trackday on 225's so if there was any danger of them popping off it would have happened then as I was thrashing it and often asking for more grip than the tyres could give in the corners!

Did you go for Bridgestone Potenzas??

vectra

A couple of things to put in.

1)
215/45/18
225/45/18

The discrepancy between both is smaller than if you use 225/40/18's

Speedo reading will be marginally out.

2)

Those Potenzo 050's are not great when you put the foot down in damp/wet weather in my car. Your's apparently has more oomph than mine so will suffer more.

3)

On the briskoda forum tyres have been discussed at lenght,
One topic has been changing from manufacturers specs (your's being 215/45/18)


Some people have got caught out with insurance in the event of an accident. Tyres being wrong sizing.

Just something to think about

vectra

vectra wrote: »

A couple of things to put in.

1)
215/45/18
225/45/18

The discrepancy between both is smaller than if you use 225/40/18's

...........

Indeed, the profile is a better match by 2mm theoretically (but when you include the actual thread etc the 225 40s would suit better) but the 225 45 18s may not take as kindly to lowering as they are a fair bit chunkier than 215 45s

MetzgerMeister

A few more things to note:

The tyres currently on the car (since I bought it) are Kormoran 225 45 R18 and they don't feel great.

Due to negative camber on the rear wheels, the wheels are like this: / \ and therefore, the inside of these tyres wear down very quickly indeed. It was even pointed out to me at my last (and first) NCT. It passed nonetheless.

b318isp

einheisserschre wrote: »

A few more things to note:

The tyres currently on the car (since I bought it) are Kormoran 225 45 R18 and they don't feel great.

Due to positive camber on the rear wheels, the wheels are like this: / \ and therefore, the inside of these tyres wear down very quickly indeed. It was even pointed out to me at my last (and first) NCT. It passed nonetheless.

That's negative camber. Wider tyres will not help this. Maybe a full alignment is needed too. Or you're not driving hard enough .

MetzgerMeister

b318isp wrote: »

That's negative camber. Wider tyres will not help this. Maybe a full alignment is needed too. Or you're not driving hard enough .

Yes, hence why I said negative camber in my post and you edited it in yours to make me look like a fool

Problem is, no tyre shop in my town has the right settings in their alignment/tracking computer for my car.

b318isp

Toe settings can also effect camber :rolleyes: as the suspension flexes, so you start there (I don't know what can be adjusted on your car however).

W.Shakes-Beer

Nissan doctor wrote: »

The sidewall measurment on a tyre is a % of the width of the tyre.

So 45% of 215 is a different height to 45% of 225.

I stand corrected

stealthyspeeder

einheisserschre wrote: »

Did you go for Bridgestone Potenzas??

I had pirelli P-zero's, which were good but didnt last as long as I expected, some dunlops which were good, the bridgestones RE050A's were the best but could only afford the 2 at the time though.

Nissan doctor

einheisserschre wrote: »

Yes, hence why I said negative camber in my post and you edited it in yours to make me look like a fool

Problem is, no tyre shop in my town has the right settings in their alignment/tracking computer for my car.

If the machine is a decent one and the operator knows what they are at then they don't need to have the specific settings for your car to set it up properly.

You should be able to tell them what driving style/handling characteristics you want and they should be able to set it up accordingly.

unkel

Gophur wrote: »

Your speedometer will read 1.38% less, if you move from 215 to 225 tyres.

Your mileometer will also read less by the same amount.

http://www.tyresave.co.uk/tyresize.html

What he said. I use this calulator myself, it has been on the internets for donkeys years