18' Alloy wheels question.

bretttp1

I'm looking at a second hand car at the mo and it currently has 18-inch alloy wheels but the seller has the original 17-inch alloys that came on the car.

My question is would you keep the 18s or go back to the 17s? Its just that I will be driving this car on country roads and I'm worried that with 18s and 45 tires I'll end up getting bulged tires all the time.

Any opinions.

cantdecide

Do you know the width of the tyre? What kind of car is it? age? mileage?

Generally, 18s are much harder to live with but not impossible, especially compared to 17s- they're won't be a huge difference. If you're used to flinging your car around the country with gay abandon, you'll have to take them off and go for some 16s or else learn to slow down and be vigilant. I think I'll be haveing my 18s fitted tomorrow and God knows I'm annoying to be behind if you're a white van man!

Will he give you both sets of wheels??

Anan1

If you drive like a granny (but know how to park) and appearance is paramount, then you'll be fine on the 18"s. If, however, you drive in any way quickly then put the car back on 17"s.

scaldybelt

Go for the 17's.....sell the 18's privately if you get both sets.

I put 18's on mine last year, and regretted it ever since - except when the car is clean!!!

30% of my daily commute is on country roads and it took me a few weeks to learn the location of the bad spots. I've had the wheels off about 4 times to repair bulges to the rim on both of the front wheels. I would be losing up to 5psi overnight each time they got a knock - let alone the affect on the steering.

cantdecide

I already had different 18s (255/35s on cheap RS6 knockoffs- everyone kept telling me I had flat but of course I never did) on this car and I thought I was going to be on a cushion of air when i returned to the original 16s- I was surprised though cos there wasn't much difference.

I've had plenty of 17s and 18s in my time and I wouldn't say it's not a categorical no for the 18s, a lot depends on how good the car is and how good the tyres are.

cashmni1

Go for the 17's espically if they are the designed wheel for the car. 18's just look good and make the car unstable at higher speeds, plus mpg goes down with the bigger wheels.

Masada

there wont be very much if anything in the difference between 17 and 18s., if the car had 17s as standard then the gearbox and diff will be perfectly capable of running the 18s., with a lot of mid sized cars you can get gearbox trouble from the increased size, particularly in a lot of VAG 1.4-1.6 motors like the golf etc where people fit those replica GTi wheels that weigh about the same as a small country aswell as the diameter over the original wheel.,

JoeA3

Can't understand myself how people have so much trouble with 17/18 wheels... I've had one or the other now on 2 cars for more than 3 years and not a single puncture. I've never replaced a tyre! Perhaps if the car was factory-fitted with the larger wheels, as mine have been, maybe that helps.

Sure, the ride is a bit harder and you need to be a bit more careful when parking, but the appearance makes up for it.

cashmni1

cashmni1 wrote: »

make the car unstable at higher speeds, plus mpg goes down with the bigger wheels.

Unstable? I thought the Idea of the lower profile is to help grip?

Eoin

What car is it out of interest? Some cars seem to need much bigger wheels to fill the arches nicely. My old car looked fine on 16" wheels, but I changed from 16" to 18" on my current car. I do seem to have gone through more tires, but they're not particularly hard to live with. I noticed a little bit of tramlining, but nothing too bad.

antodeco

I went from 16's to 17's. Dropped profile from 55s to 45s, so the overall diamater is pretty much the same. At higher speeds there is definitley more noise and the balancing seems to be off (despite 4 seperate balancing) I need to replace the tyres, got 35k out of them. If you are going for 18's try and change the overal profile to something similar to the 17s.

Masada

cashmni1 wrote: »

Go for the 17's espically if they are the designed wheel for the car. 18's just look good and make the car unstable at higher speeds, plus mpg goes down with the bigger wheels.

im not sure if you mixed that up but theres no way a car is more unstable with bigger wheels. you will have increased stability with larger/wider wheels as there is more of the car in contact with the road. as it is the average car might have a tire of about 5 inches wide there is always aproximately 1 inch of the tire thread in contact with the raod, with aftermarket wheels the average is more like 7.5 inches wide giving you around 50% more tire surface area in contact with the road. the down side is a lot of the time it can increase road noise but that can also depend on the tire design.
Also the MPG can be effected with larger wheels due to the engine having to try just that littl bit harder to turn the bigger wheel. this only comes into effect if the wheel and tire is larger than the standard wheel and tire which isnt always the case as people get larger wheels and lower profile tires. In theory though the car should be faster in top speed but it would only be very slight if any difference to the standard.

antodeco

Yup, if in doubt about size/speed variances:

http://www.miata.net/garage/tirecalc.html

chucky1989

Jesus mate, I would deffo go back to the 17's, country roads are a ---- for that sorta thing. I used to have 18's and was gettin bulged tyres jus from goin over ramps. Not worth it man.;)

Anan1

JoeA3 wrote: »

Can't understand myself how people have so much trouble with 17/18 wheels... I've had one or the other now on 2 cars for more than 3 years and not a single puncture. I've never replaced a tyre! Perhaps if the car was factory-fitted with the larger wheels, as mine have been, maybe that helps.

Sure, the ride is a bit harder and you need to be a bit more careful when parking, but the appearance makes up for it.

It really depends on how hard you drive. 18"s are fine on a gently-driven car. I had an Audi A8 4.2 quattro until recently, on factory 18"s. It was well set up for the 18"s, but would have been both more comfortable and faster on 17"s. And I spend no more time looking at my wheels than I do looking up my exhaust pipe.;)

mickdw

I run 225 45 18 on worst roads in ireland. No problems over 2 years. I do avoid potholes. Car is designed for them though. Wouldnt fit 18s if not specified for the car. Lots of tyre rub etc in many cases where they are fitted on the wrong car.

Eoin

vtec wrote: »

im not sure if you mixed that up but theres no way a car is more unstable with bigger wheels. you will have increased stability with larger/wider wheels as there is more of the car in contact with the road.

I think wider tires are more prone to aqua-planing?

Anan1

eoin_s wrote: »

I think wider tires are more prone to aqua-planing?

Quite true. Wider tyres also tend to lose grip more suddenly than narrower ones.

bretttp1

Thanks for the replies guys, the car is an Alfa 147 I think I'll go with the 17s (that seems to be the general opinion here) even though the 18s look good

Would running the car on 18s also make the car more likely to have suspension and alignment issues from small knocks and bumps from normal driving?
I'm thinking that that bit of extra cushioning from running 17s would be slightly more forgiving on that front.

O7Pat

If u go with the 18's check will 45's fit properly or look squashed,

Some retro fit 18's have 40's on them (which in my opinion are that bit too small for country roads, have ending replacing tyre as a result of minor enough potholes)

niceirishfella

bretttp1 wrote: »

I'm looking at a second hand car at the mo and it currently has 18-inch alloy wheels but the seller has the original 17-inch alloys that came on the car.

My question is would you keep the 18s or go back to the 17s? Its just that I will be driving this car on country roads and I'm worried that with 18s and 45 tires I'll end up getting bulged tires all the time.

Any opinions.

Go back to the 17's if you dont want to shake the car asunder and suffer from a bad back. I know this from nasty experience.:(

Seth Brundle

There is also the cost difference between 17" and 18" tyres.
17" Goodyeay Eagle F1s for my car are under €200 each (235/45 front being about €30 cheaper than the 255/40 rears). The equivalent tyres in 18" are about €100 dearer.

furtzy

18's came as standard on mine and I've never had any problems. Just put 2 new Vredestein Ultracs on it for €300 fitted so tyre prices aren't an issue

Seth Brundle

I see Vredestein Ultracs did well in an AutoExpress review. €300 for two 18" tyres seems very very cheap! What size are they?

cantdecide

18s are probably a little bit too big for a 147. 17s will be just fine IMO. OEM alfa alloys are quite nice too.

furtzy

kbannon wrote: »

I see Vredestein Ultracs did well in an AutoExpress review. €300 for two 18" tyres seems very very cheap! What size are they?

225/45 R18

Got them in Mc Quaid tyres in monaghan. He is always by far the cheapest and with a great service.

Got 40k klms out of the last Ultracs and they are superb in the wet so I always go for them

unkel

I've 18" tyres on my 7-series. They are fine on motorways / national roads, but not so great on bad surfaces. The previous owner of my car told me he came close to buying a set of 17" wheels / tyres and I didn't know what he was on about at the time, but I do understand now. I once burst a brand new tyre in a deep pothole

furtzy wrote: »

225/45 R18

That was cheap! They're €181 on eiretyres. In my size (255/45R18) they are €196, which is a good bit cheaper than the original Contis

I'll try and remember this when changing next

bretttp1

Actually just found out that the originals are 16" 205/50's so they should be fine for country roads, pity though I liked the look of the 18's

This car also had lowered suspension would you guys keep the lowerd suspension with 16" wheels or would the car be sitting very\too low?

blackbox

I'd go for the originals - plenty of people don't know enough about steering geometry and buy larger wheels with incorrect offset.

As for the lowered suspension....maybe you should consider a different 147.

furtzy

blackbox wrote: »

I'd go for the originals - plenty of people don't know enough about steering geometry and buy larger wheels with incorrect offset.

As for the lowered suspension....maybe you should consider a different 147.

I agree totally. Wouldn't touch anything modified. Bound to be other better examples out there that haven't been molested

Anan1

bretttp1 wrote: »

Actually just found out that the originals are 16" 205/50's so they should be fine for country roads, pity though I liked the look of the 18's

This car also had lowered suspension would you guys keep the lowerd suspension with 16" wheels or would the car be sitting very\too low?

I'd have to agree with blackbox & furtzy here - you should only consider buying an Alfa that has been very sympathetically maintained.