Handling better on 16"s or 17"s?

[weinelm]

There's plenty of stuff on here about spoiling the handling if you go larger than 17 inch rims. I was wondering how stock 16s compare with stock 17s?

 

I need to buy new tyres and currently have 225/50/R16 all round on my NA. Before I splash out on new tyres I thought I see what people think.

 

I'm interested in handling, not bling...

[Daston]

I had stock 16s with 225/50/16 and 245/45/16 I changed to stock 17"s and found the car was far more stable round corners and sticks to the road alot better in the dry.

[weinelm]

Cool, have you got the stock sizes on there: 235 front and 255 back? I thought maybe these might be overkill for NA?

 

Does the car feel any 'sharper' with the lower profile you get with 17s. I'm really keen on getting good steering feel and turn-in and wonder if the 17s would make a different to that?

[Homer]

I had stock 16s with 225/50/16 and 245/45/16 I changed to stock 17"s and found the car was far more stable round corners and sticks to the road alot better in the dry.

 

Same, here. Agree with you completely, I also found the grip out of coners considebly better with the 17's, but thats on a BPU TT.

 

Edit: weinelm, the stock sizes for the 17s are 235/45 front, 255/40 rear. I only remeber the whole car feeling more stable and easier to drive quick on the 17s.

[Mike M]

I agree with Daston there, my NA had stock 16's and the TT has stock 17's and feels alot sharper on the turn in. Part of that will be due my NA being an Aerotop though, oh and the TT has Bilsteins instead of KYB's.

[JamieP]

plus when your on 17's you can upgrade to uk brakes which is a great advantage if your racing around;)

[Mike M]

and the calipers look nicer.

[Tom S]

Cool, UK brakes sorted and I run on 19's!!

[weinelm]

Yeah, I like the idea of being able to fit UK brakes under (although I don't need any more excuses to spend money!).

 

Thing is I don't find the car is particularly lacking in grip with the 225/50/R16s all round, so if I get some stock 17s with 235 and 255 rubber I think that might be more grip than you need for NA - I still want to be able to find the limit occasionally

 

I'd like the sharper turn in that might come from lower profile tyres on 17s. So may be I should look at some aftermarket 17s with 225 rubber all around?

[Daston]

Oh dont get me wrong you can still get the back to step out and light up the rears if your not careful recently I have been finding hard not to squeel the rears when pulling out of junctions even when I am not really trying.

[letmeshowyou]

I had 255/40/17s on the rear of my N/A and braking traction really wasnt a problem!

[AJI]

generally speaking a lower height tyre sidewall will handle lateral forces better.

therefore 17's would be better in that sense, but then 17's will generally weigh more than 16's, so you have more inertia to overcome when accelerating or braking.

If handling is your main concern then 16's on lower sidewall heght allround would have the effect of lowering your centre of gravity. But your speedo reading will not be reading an accurate MPH/KPH.

[weinelm]

That's an interesting idea. Put, say, 45 profile tyres on the 16s. That would effectively bring the whole car about 10mm closer to the ground.

 

I'll have to do a quick photoshop, to check the wheels don't look too silly/small and I guess the car would look like it was riding about 10 mm higher due to the gap in the arch.

 

Apart from the speedo reading wrong (I think it would read about 4% too low)are there any disadvantages to doing this?

 

Would I be likely to notice any difference in handling between 50 profile and 45 profile tyres?

[AJI]

well the biggest difference would be noticed in the tyre compound more than anything else. If you buy some expensive soft compound tyres, you'd notice the grip difference straight away.

But couple this with reducing the sidewall height and you'd really notice the difference on cornering. (Aswell as ride comfort - but this is always compromised when you setup up a car for handling).

But as you point out they may look silly with a large wheel arch gap.

 

On the market at the moment there are some basic spring lowering devices which may also help out. Halfrauds currently sell them. They won't improve your spring but they'll lower your car to match the reduced sidewall height in tyres. (I think they work as a basic g-clamp type setup).

 

Also to bear in mind is that a 45 profile tyre is not simply 5mm lower than a 50 profile tyre. Its a ratio between the sidewall height and the tread width.

The important factor when working out error readings on the speedo is the rolling radius.

[weinelm]

Yeah I should have said, I was assuming 10mm difference in sidewall height when comparing 225/50/R16s to 225/45/R16s.

 

I have got a set of lowering springs in the garage, if it did look too silly. Although I wasn't very keen on how they effected the handling, so I wasn't really planning on putting them back on.

[AJI]

Lowering springs are good for the track as you need a stiff setup on a dry racing surface, but they really compromise road performance with our bumpy roads and also compromise wet weather handling.

I'd only think about doing any of the above if you're into a lot of trackdays. Otherwise you road handling and ride comfort for everyday use may well take a dive.

But the above posts are a cheap way of improving handling (in a lap time sense of the word).