What tires to choose? 225/45 or 234/40

[zafira]

Hello. My vectra has stock tires 225/45-18 wheels. I need new summer tires for the season and wonder if I should go for 235/40 instead. How would the comfort be? Will the 235/40 be much harder to drive on?

[zafira]

Bump

[ted]

The 235 would have a sidewall around 7mm more shallow so less springing effect from the tyre for sure.

I personally wouldn't fit a tyre with an aspect ratio lower than 45, the 50's I have on my Signum resist flex on cornering pretty well in my opinion so I imagine 45's would be as low as anyone needs to go for a road car?

Unless you like getting your teeth rattled ?

[Signum-Steve]

The 235 would have a sidewall around 7mm more shallow so less springing effect from the tyre for sure.

I personally wouldn't fit a tyre with an aspect ratio lower than 45, the 50's I have on my Signum resist flex on cornering pretty well in my opinion so I imagine 45's would be as low as anyone needs to go for a road car?

Unless you like getting your teeth rattled ?

I have 225/40/18 on my Siggy, I have a eibach pro kit fitted aannnndd I still have all of my teeth . Yes the ride is firm, but I will also add it is very smooth with an excelent ride quality, with very little body roll when cornering. This may have something to do with my eibach's

I'm thinking going with 235/40/18 next time I re-new my tyre's to give a little more protection to my rims. The profile will be slightly higer as the profile is a % of the tyre width. I love the ride quality of my current set up. Its far better than the standard set up. however everyone has their own preference.

[Big Sig]

235/40/18 is a closer match to the 215/50/17 than the 225/45/18.

Having had 235's I'd fit them over the 225's as they look like they fit a lot better. It desn't make that much difference to the ride quality over the 215/50's either.

[Signum-Steve]

235/40/18 is a closer match to the 215/50/17 than the 225/45/18.

Having had 235's I'd fit them over the 225's as they look like they fit a lot better. It desn't make that much difference to the ride quality over the 215/50's either.

Here is a little info for ya......

The 50 indicates that this tire size's sidewall height (from rim to tread) is 50% of its section width. The measurement is the tire's section height, and also referred to as the tire's series, profile or aspect ratio. The higher the number, the taller the sidewall; the lower the number, the lower the sidewall. We know that this tire size's section width is 225mm and that its section height is 50% of 225mm. By converting the 225mm to inches (225 / 25.4 = 8.86") and multiplying it by 50% (.50) we confirm that this tire size results in a tire section height of 4.43". If this tire were a P225/70R16 size, our calculation would confirm that the size would result in a section height of 6.20", approximately a 1.8-inch taller sidewall.

[ted]

I would also add that we in the UK should really factor in the state of the roads we typically encounter on a daily basis

I Have hit some epic pot holes over the last 2 0r 3 winters, suffered some tyre bulges as a result but thankfully the alloys have always survived intact.

Not so sure a 40 section cover would have let me off so lightly

But hey, we must all spend our money on what makes us happy, possibly taking the risk our wheels will end up the shape of 50p coins if we dont watch where we're going.

[zafira]

Thanks for reply everyone. Yes, 40 profile would be harder. But a wider tire on the same alloy would give more suspension then a less wide because the angle of the sidewall. Do you agree? . I think 235 would look better then a 225, but comfort is important for me. So thats why am ask you people for your experience.

[UncleMelon]

I think I'll be going for 235's next time, just for a little more protection more than anything... Can you put 245/35/18s on?

[DAVIDD88]

I have 225/40/18 on zaffy and its not to bad