Tyre question

Slattsy

Hey lads, a quick one for you.

What would be the main difference between driving with 17" tyres to driving with 19" ones.

I guess it's a firmer ride? Anything else. Is fuel consumption improved?

Supergurrier

More vibration/harsher ride (if 19's im guessing they will be lower profile) Clutch+steering rack also under more pressure depending on car's idea wheel size

Personally im changing down a size for this very reason, also depends on car tbh as some cars have much bigger arches than others

SpannerMonkey

god no fuel consumption on 19' tyres would be worse than 17 ' also it depends on the car , some cars become awful to drive on 19's , my car has 19's on it but they are standard so it can handle them fine , but not every car can .

other than that expect a much harsher ride and to pay a lot more for tyres .
other than that again if the car isnt designed to take them you may notice the wheels tramlining a small bit ,

BUT THEY DO LOOK HELLA COOL :cool::p

CiniO

Slattsy wrote: »

Hey lads, a quick one for you.

What would be the main difference between driving with 17" tyres to driving with 19" ones.

I guess it's a firmer ride? Anything else. Is fuel consumption improved?

Assuming you want to keep the same wheel diameter, 19 inch tyre would be much lower-profile than 17".
This would provide better handling on good quality surfaces, but also rougher ride (you would feel every bump more severly).

Also usually with 19" lower profile you would have them wider, which would cause increased fuel consumption, and poorer quality of driving on bad roads especially on ruts.

Slattsy

I guessed the ride would be harsher.

What do you mean by "lower profile"?

Supergurrier

Slattsy wrote: »

I guessed the ride would be harsher.

What do you mean by "lower profile"?

Less sidewall etc

CiniO

Slattsy wrote: »

What do you mean by "lower profile"?

B

Ronnie Beck

CiniO wrote: »

This would provide better handling on good quality surfaces

No it wouldn't. Purely aesthetics.
Is there a smooth surface in Ireland that requires better handling anyway?

Slattsy

Supergurrier wrote: »

Less sidewall etc

Yes I get you.

So you have two cars, same model, year, price etc.
One has 17" alloys and tother has 19" alloys.
What do you go for?

CiniO

Ronnie Beck wrote: »

No it wouldn't. Purely aesthetics.
Is there a smooth surface in Ireland that requires better handling anyway?

I don't think there is.
But surely when driven on F1 race track, 19" with low profile tyres would be better than 17" with higher profile.

CiniO

Slattsy wrote: »

Yes I get you.

So you have two cars, same year, price etc.
One has 17" alloys and tother has 19" alloys.
What do you go for?

I'd definitely go for 17" as tyres would cost hell lot cheaper, and it would be easier and nicer to drive on Irish road.
If I was to drive mostly on country roads, I would probably even consider downgrading to 16"

Slattsy

WCiniO;81603141]

I'd definitely go for 17" as tyres would cost hell lot cheaper, and it would be easier and nicer to drive on Irish road.
If I was to drive mostly on country roads, I would probably even consider downgrading to 16"[/Quote]

Is there a way of gauging fuel consumption against the other?

I genuinely wouldn't have thought fuel consumption would have been a huge issue so im quite surprised by this.

Would i be right to say that the bigger alloy is purely for looks and has no advantage over a smaller alloy?

CiniO

Slattsy wrote: »

Is there a way of gauging fuel consumption against the other?

I genuinely wouldn't have thought fuel consumption would have been a huge issue so im quite surprised by this.

I doubt it would have huge impact on fuel consumption.
Also as I mentioned it's mostly the tyre width which increases fuel consumption. So if your 19" wouldn't be wider than 17" there shouldn't really be any difference in fuel consumption.

Would i be right to say that the bigger alloy is purely for looks and has no advantage over a smaller alloy?

19" alloys on Irish roads would be pretty much useless when it comes to handling and driving comfort.
If you were travelling a lot in Germany on autobahns with speeds exceeding 200km/h you could possibly benefit from them.
In Ireland for most cars 17" would be the biggest reasonable size.

I know people put bigger rims for looks, but I can't really understand it as IMHO car with such huge rims and low profile alloys looks stupid. I don't like them.

Slattsy

Thanks mate.
Food for thought.

Ronnie Beck

They don't improve performance in any way no matter how you look at it. MPG decrease as the wheels are heavier and will decrease further if you increase the surface area on the road. I think 16 inch wheels are the most common and give you the best value on tyres.

Maybe if your building a car for a silky smooth track they'll be good but even there your looking at 18's just to allow you to use bigger brakes. Not really relevant to road cars.

They do look nice up to a point. I've seen a 318 today with little or no sidewall at all. Didn't look great. Can't have been comfortable on a suspension designed for much bigger tyres. Not in the whest anyway. When the average pothole is deeper than your tyre profile your just takin the p]ss

CiniO

What size of car are we talking about.
Because it's also one of the main factors.

Slattsy

It's an Audi A5.
Living in dublin so mostly driving on good roads.

Anjobe

Slattsy wrote: »

It's an Audi A5.
Living in dublin so mostly driving on good roads.

If the A5 is like any Audi I've driven the ride will be rock hard on the smaller rims, the 19s would probably be unbearable!

CiniO

Slattsy wrote: »

It's an Audi A5.
Living in dublin so mostly driving on good roads.

Hahahaha
That made me laugh
What I meant earlier by good roads is definitly not what you'we got in Dublin and around (maybe with few exceptions)
Anyway - a5 is not big enough car to justify 19 inch wheels for everyday use imho

b318isp

There is also a good chance that the weight of the wheel/tyre combination will be heavier, and the centre of mass further out. This increases the flywheel effect of the spinning wheel - which can affect braking and acceleration, turn in speed, the ability of the suspension to react to bumps, etc.

A little OT, note that Formula 1 tyres have large sidewalls with small wheels - and rally cars are generally 50-65 section, and often run in the 14-16" diameter range.

Slattsy

CiniO wrote: »

Hahahaha
That made me laugh
What I meant earlier by good roads is definitly not what you'we got in Dublin and around (maybe with few exceptions)
Anyway - a5 is not big enough car to justify 19 inch wheels for everyday use imho

Ha ha don't be laughing at me! I can do that myself.

I drove the motor last night, only briefly on a stretch of road. I can't say the car felt in anyway bad on them.

Fatswaldo

Formula 1 car tyres have large profiles due to FIA rules and bear no resemblence to standard car tyres. the sidewalls are massively stuff with little or no deflection.

Rally cars use the higher profile due to the road conditions that prevail - to prevent damage to alloys on rough sections.

Touring cars which run on tarmac tracks use very low profile tyres.

My own car comes factory fitted with 19" rims and run-flat tyres. The car is set up for them and there are no issues around towns or on good roads. Ive driven on them in France and UK and they feel perfect. However, due to the shocking state of irish country roads, I've mangled so many tyres and alloys that I've changed to 17" rims with the higher sidewall. Doesnt look near as good but saves a fortune on repairs and replacements.

Personally I think the A5 would need at least 18 inch wheels to look right, sports coupes with wheels that are too small and high profile tyres just look out of proportion imo.

Anjobe

Eduardo Dry Ping-pong wrote: »

Personally I think the A5 would need at least 18 inch wheels to look right, sports coupes with wheels that are too small and high profile tyres just look out of proportion imo.

But should a cosmetic factor override all the practical considerations? Personally I'd rather have cheaper tyres and a more comfortable car, especially when the car rides far too firmly in the first place!

b318isp

Fatswaldo wrote: »

Formula 1 car tyres have large profiles due to FIA rules and bear no resemblence to standard car tyres. the sidewalls are massively stuff with little or no deflection.

Rally cars use the higher profile due to the road conditions that prevail - to prevent damage to alloys on rough sections.

Touring cars which run on tarmac tracks use very low profile tyres.

The conclusion is that motorsport tyres, wheels and suspension are designed specifically for their application - and perhaps there is limited carry over of comparison to the compromises of road use.

In general though, unless specifically designed to take bigger rims, road cars tend to perform worse as wheel size increases.