disadvantages of larger wheels

inlimboland

Thinking of maybe increasing the size of my wheels, standard passat alloys, think they are 16", upto 18". Is there much noticable difference with ride quality, fuel efficiency, or any other wear and tear , or anything else i should be wary of?

ChristyCent

If the tyres are low profile expect a bumpier ride than your used to. Also they'll slow you down and increase fuel consumption. I have 13's 15's and 17's for my car and its quite noticeably different driving with each set.

On the plus side big wheels look cool

glaston

Watch out for extra cabin noise too.

tossy

pros

Looks better (opinion) esp if lowered
Better road holding due to lower profile/wider tyre.

Cons

Can be noisier (varies from tyre to tyre)
Can look silly if not lowered- see above
The lower the profile the less a tyre lasts e.g a typical 16" tyre could last 30k miles where as a typical 18" one could last 12k miles.
Increased chances of buckling the wheel on potholes esp if you go for soft replicas.

Dartz

Unsprung weight increases, bollocking up your ride. This also means more power from your engine goes solely towards accelerating your wheels, rather than your car.

Tyre profile decreases, ruining your ride further as the sidewalls can't deflect any more. (This is why low profile tyres are popular in certain types of racing)

The only benefit is, that it looks good. Otherwise it's a bloody waste.

Berty

I had a Passat with 15"'s and now have an Audi with 17"s. I would take the 15"s any day for ride quality.

I would sacrifice ride quality every time for style though.

Moving up to 18" you will be provided with the correct tyre wall size to compensate for the increase because otherwise your speedometer will not give you the correct speed.

tossy

Dartz wrote: »

Unsprung weight increases, bollocking up your ride. This also means more power from your engine goes solely towards accelerating your wheels, rather than your car..

A good quality 18" wheel can be lighter or at least as light as most 16/17" alloys so the unsprung weight argument only works if he goes for reps,some of which can be really heavy.

inlimboland

didnt think there would be that much of a difference only moving up 2"?
Im looking at a place up the north with fairly cheap sets available

tossy

There are probably replica wheels so beware of the quality,reps manage to be both extremely heavy and very soft - figure that one out.

inlimboland

about the fuel efficiency, how much of a difference are we talking?

tossy

inlimboland wrote: »

about the fuel efficiency, how much of a difference are we talking?

I've never noticed any difference in fuel efficiency when i have changed alloys in the past.

What engine is in the passat?

inlimboland

its a diesel 130bhp, a set of alloys for around 350 pounds, would these be considered too cheap? i.e probably too heavy and too soft?

Eoin

inlimboland wrote: »

didnt think there would be that much of a difference only moving up 2"?
Im looking at a place up the north with fairly cheap sets available

I noticed a difference moving from 16" to 18" alloys; the ride was a lot harsher and there was more tramlining. I paid a lot more than 350, and they were still quite soft and seemed to buckle quite easily. I got an awful lot of punctures as well, which I can only assume is related (some people say there's no connection between low profiles and punctures though). If I were to do it again, I'd go with genuine 17" alloys as a compromise.

inlimboland

Thanks for the responses, it seems that it may not be such a great idea

Fishtits

immediate concern is that your geometry is shot to pieces, ie it looks good but it handles worse than OE, may not concern you if you trundle about urbania...

Purists opinion... bastardised motor.

bazz26

This site is handy for calculating what different wheel sizes can have on your speedometer:

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

JHMEG

tossy wrote: »

pros

Looks better (opinion) esp if lowered
Better road holding due to lower profile/wider tyre.

Cons

Can be noisier (varies from tyre to tyre)
Can look silly if not lowered- see above
The lower the profile the less a tyre lasts e.g a typical 16" tyre could last 30k miles where as a typical 18" one could last 12k miles.
Increased chances of buckling the wheel on potholes esp if you go for soft replicas.

More cons:
Slower acceleration (if tyres haven't been downsized proportionately, which is rarely the case)
Worse fuel economy
Speedo reading incorrectly
More expensive tyres
Smaller choice of tyres

inlimboland

lookin at "18 inch GTI ALLOY WHEELS" on e bay, roughly 540e with delivery from uk, any thoughts on these? or similar e bay wheels
http://cgi.ebay.ie/18-GTI-ALLOY-WHEELS-VOLKSWAGEN-PASSAT-TYRES_W0QQitemZ350255370760QQcmdZViewItemQQptZUK_CarParts_Acc_Wheels_tyres_Trims_Car_Rims_ET?hash=item518cd8d208&_trksid=p3286.c0.m14

Eoin

First thing to do is find out the make and model of the tyre.

Absurdum

tiny brakes look really stupid behind big wheels

inlimboland

thanks , just sent them that question, i presume these are replicas?

Eoin

inlimboland wrote: »

thanks , just sent them that question, i presume these are replicas?

I'd be shocked if they were real at that price, and I can't see the tyres being any good either. Even a set of budget tyres on a site as cheap as this one is going to cost you £200.

inlimboland

Ive found a 2nd hand set of golf gti 18" alloys with tyres, taken from an 06 golf for 480e, anything i should look out for before i take a look?
Is there any way to tell if they are genuine or replicas?

mickdw

I dont think the gti alloys look good on a passat. I wouldnt go any bigger than the largest size available as an option from the factory for your car. That would be 17" Id say.
You also need to be sure that you get a suitable offset or your handling could be destroyed

inlimboland

what do you mean "suitable offset"
Bear with me im pretty clueless when it comes to this..

mickdw

inlimboland wrote: »

what do you mean "suitable offset"
Bear with me im pretty clueless when it comes to this..

The offset dictates how far inward/outward your wheels sit on the car. With the wrong offset, the wheel could be out too far and the tyre could rub on the wheel arch. Basically, the offset measurement is the distance from the centreline of the tyre to the mounting surface that sits against your wheel hub.

inlimboland

ok thanks for that, whats the deal with fixing the offset, how is it done?

waraf

In my experience there is a very, very good chance that you will buckle a wheel with big alloys and very low profile tyres. Potholes will scare the s**t out of you and when it rains you'll be even more worried because it's very difficult to spot potholes when they're full of water and even if you do spot one you can't tell how deep it is.

A friend of mine hit a pothole in the rain with 17" alloys - result: two buckled wheels and two tyres that instantly deflated when the wheels buckled. Fun times....

Mr.David

Some other things to note:

It will affect your steering feel hugely and is unpredictable. If you are into steering feel (to be honest the Passat is poor anyway in this regard - no offence!) it will be an issue. Wheels are incredibly important in terms of vehicle dynamics. I have driven cars back to back (same car) just changing the wheel style. Same size wheel, same tyre etc just different wheel style. The stiffness of the wheel (both laterally and radially) in conjunction with the centre of gravity and moment of inertia will affect ride, handling and steering response quite dramatically. Even the ratio of stiffness from front to rear will matter.

I think if you are really into your driving experience and these sorts of things matter then dont do it unless you are prepared to go further than just wheels. However if you dont really think about your ride quality/steering feedback etc and its purely aesthetic go for it. The car will be grand on 18s, maybe just not as good as previously.

inlimboland

I know , but it'll eat me up inside if i dont try it..:D
If i knew how to insert an image into this post i would show you what im talking about

Eoin

Upload to somewhere like www.photobucket.com and it will give you the code so you can link to it here. If the picture is already on the internet, then get the address of it and put it in like this [noparse][/noparse]