Tyre profile vs ride comfort

[Fletch350]

I'm finding conflicting info on this,currently on standard 18s with 45 profile tyres.if I switch to 19s with 35 profile is the ride going to drastically change for the worse? (Bad back sufferer).

[Jetpilot]

You will certainly feel more reaction to bumps, potholes etc

[Jack94]

As a general rule the thinner the profile of the tyre, the harsher the ride will be because you've got less air to absorb the bumps.

So as Jetpilot has said, you'll definitely feel it won't be as smooth over any surface changes. 

That being said imo the 350z suits 19's perfectly so it's totally worth it 

[Ekona]

It's not just the profile size, it's also the added weight of the wheels. Extra mass there means more is transferred from the already skinny sidewalls into the suspension and in turn into the chassis. You'll also accelerate slower and increase braking distance.

 

For some the looks are worth it (and I totally get that 19s look better than 18s). For some the knock on effects aren't worth it. Your call, but in answer to your question yes the ride will be noticeably harsher, but I can't say whether it'll be too much or not. As someone who has suffered with back issues previously (seriously herniated disc L5/S) I do understand where the question is coming from, and personally if it were me I wouldn't risk anything making my back worse.

 

But then I've no idea how bad your condition is!

[longsh07]

While I don't suffer with a bad back (though I cant be the only one whose 350Z seats give them back ache!), I made the swap from 45 profile on 18's (GT4 alloys) to 35 profiles on 19's (LMGT4s), then back again, then to a 40 profile on 18's (Work T7R's).

 

The 35 on 19" was a bit too jarring and uncomfortable for me. It made the steering feel heavy and the car generally felt like it was more effort to drive.

Switching back to the 45 on 18 (stock GT4 wheels), car felt more nimble and much smoother however the change in width from my 8.5 front and 9.5 rear LMGT4's was noticeable and the car felt less planted.

Ended up settling on a set of Work T7R's with a 40 profile but 8.5 front and 9.5 rear widths. Really happy with this, Feels more nimble than 19" alloys while still feeling planted and not as crashy.

 

Also to note is that some tyres have stiffer sidewalls than others which will make the ride firmer, even between two tyres with the same profile.

Normal summer tyres will be softer than 'performance' type tyres, and trackday like / full trackday tyres being stiffer still.

Edited April 27, 2018 by longsh07

[Flashback]

It's definitely more bumpy on lower sidewall 19s than stock 18s with 45 sidewalls.  Personally I've become used to it, but my missus hates the car this way (and complains about the ride quality).  So probably not a great idea if you suffer from a bad back.

 

On the plus side you will definitely look better when they pull you out the car at A&E as you'll have a better stance (well on the car anyway )

[Fletch350]

Thanks for the replies all.I may be staying with 18s,I was suprised how comfy my car is ride wise and don't want to ruin it.my back problems are many with various discs doing their own thing over the years eventually leading to fibromyalgia. 

[StevoD]

Unless I missed it has anyone mentioned width as I'm sure a 255/35/19 vs a 225/45/18 won't be as much difference as what people think, and like for like a 225/45/18 Nokian might ride shitter than a 245/35/18 mpss

 

To many variable to give a correct answer 

[longsh07]

25 minutes ago, StevoD said:

Unless I missed it has anyone mentioned width as I'm sure a 255/35/19 vs a 225/45/18 won't be as much difference as what people think, and like for like a 225/45/18 Nokian might ride shitter than a 245/35/18 mpss

 

To many variable to give a correct answer 

I ran 255/35/19 and 275/35/19 on my LMGT4s.

Noticeable difference (imho) from stock 225/45/18 and 245/45/18 on stock GT4 alloys.

 

As above, I'm on 245/40/18 and 265/40/18 now which is a decent compromise.