i have asked this before but can't find the thread and its got a new twist to it so please bear with my guys.
i have a lovely set of 18" wheels sitting in my garage that i had on my rover turbo.
the have 215/35/18 tyres on. they will need speacers to fit and wobble bolts. i also have some 20vt wheels on at the moment and i was going to spray them gun metal and put new tyres all round.

my question is if i have a set of 18's with lowe profile tyres on will it handle better. they will both have t1r's on the thing is the new wheels weigh 12.5kg each so 3.5 kg a wheels more! but they will have less tyre movement due to the lower profile tyres and wider wheels.

its going to cost me about £300 to fit the new wheels so i don't want to mess up on them.
they will look better though

also will it help spacing out the standard wheels as i want them sitting flush with the arches if i keep them?

the other option is to get the stuff to put the 18's on and then refurbing the 16's and putting r888's on them for the summer months. is it worth doing?

The lower profile the tyre, the wider the width has to be to maintain a correct speedo. So first off if you are going to wider 18's you'll have to make sure they dont rub on the arches anywhere.

Spacing the 16's will help a bit as it widens the track of the vehicle (albeit very slightly).

Finally, although the 18's in summer, 16's in winter seems like the perfect solution (gives you time to repair any damage either set might get while they're on and saves the 18's from the winter beating) will you really switch them about? I know that once i had my 18's on my old coop, I never wanted them removed and i think i'd would just think, "oh but it looks so much better" and keep them on all the time

Plus points

Will look better
Will ride more firmly - turn-in will be improved (but see below)

Negative points

Will ride more firmly - MUCH more firmly
Turn-in might be worse as the wheels are 33% heavier
Suspension will be under-damped due to the huge increase in unsprung weight
Acceleration will be reduced, again due to the big increase in weight.
Tyres will be MUCH more expensive

The only way I'd fit 18s is if they weighed roughly the same or less than the 17s I currently have (which are already slightly lighter than standard)

Remember that rotational weight increases have a double-negative effect. They increase the overall weight of the car (obviously) but they also add to the rotational mass, which gives a hugely disproportionate effect on performance.

Don't believe me? Why do owners lighten their flywheels? - its to reduce rotational mass. Even a couple of KG off the flywheel can make a difference to acceleration. Adding a HUGE 14KG to the mass of the wheels is like adding 14KG to the flywheel - you WILL blunt the performance. And this is before you've factored in the likely increase in the weight of an 18" tyre over the stock item.

IMHO, you should spend your money on something that will improve the dynamics of the car, not just the looks.

Agrre with what Nigel is saying, I have 17" race wheels are lighter than the standard 16" wheels by about 2kg per corner. - you want to be taking it off not adding it (weight)

If you want 18"s ideally you should get some light ones thinking Rays, P1 buddy club etc that tend to be forged and super light.

Rotating mass is the worse type (at least it is not at engine revs like a flywheel) but it is unsprung and rotating

So from a performance prespective bad idea really, so style or function, your call

f i am honest i bought them for the rover and it didn't affect it really. i understand the idea behind the flywheel but then its only 2 driven wheels so thats all that is affected by the extra weight.

the tyres are double the price which isn't good and i do a fair amount of miles.

the main thing i think i will notice are the fact it will be a much crashier ride and that turn in will be blunted but then tyre flex won't be as bad and less tyre bounce.

the weight of the spacers and longer bolts won't help either.

im not even sure they will clear the brembos yet but it will also allow me space for larger brakes if i want and better cooling for the brakes too. but extra weight for the brakes to deal with.

really the car is just a road car and i think they will look nice but don't want them to ruin the car.

also the car is going to be lowered. either koni's and ebiech or fk silverlines (bravo topmounts) not sure yet. this has plus and minus.
18's will offer a bit better clearance and less likely to ground out when i get my larger downpipe and lower brace.

it will be lot more crashy with uprated suspension and worried it will cause major issues with rough roads.

also the point of going to get all this if the wheels will counter act the coilovers.

what i would really like is some nice 17's like pro racer 2's or oz wheels or some bbs split rims but its so expensive and i don't have that much money.

Why?

it should keep the speedo the same but not a massive problem.
the other thing is my bro will give me £300 for the 18's so maybe better lay £300 on making the car handle and go better or fixing the dam thing.
still think it would look stunning with the 18's on though :-( such a hard choice.

might be a daft suggestion, cant you get the spacers and try the wheels and see what you think... if you dont like it, sell the wheels to your bro and all it would have cost would be the spacers?!

the spacers are about £100 pre axle so not cost effect.

Big is not always better when it comes to wheels.. A few good valid points have been made above. My old Punto GT had 17's on..Ride was awfull.. Went down to 15's.. It was the RIGHT thing to do.. Big heavy wheels may look good but will slow you down..
Its all about reducing the un-sprung weight.

stick with stndard mate i have had mine done in gloss black and they look stunning on my sprint blue
ash

just wished they made the coop wheels 17's and filled the arches :-(
the thing is io really dislike the look of standard wheels but don't want a crap handling car. haven't got any really money for new wheels.

If you have enough money for £100 spacers and 18" tyres, then you have enough for 17" wheels - you just need to keep your eyes open.

I paid £400 for my Team Dynamics ProRace 1 (with tyres) and I managed to find these wheels (with new tyres) for just £200



I'm biased, obviously, but I rather like the ProRace 1 (and 1.2) - in 17" they are just 19lb / 8.6kg

i love pro racer wheels. i have had them on 3 car so far and think they are great.
i have had pro racer 1 , 1.5's and 2's. think i liked the 2 the most.
where they second hand as they are alot more than that new.

have toy got a link to those wheels pictured nigel as i really like them.

the only pro racers i have seen to fit the coop are 16's and are over £450 and i would rather not get 16's even though they would be very very light.

ProRace 1s have no embossed writing in the rims, which I prefer

The wheels in the piccy are Rota Attack - pretty sure they won't fit over the Brembos without spacers

They look good though

they do look very nice. the problem is by the time i have bought spacer,wobble bolts and 17's and put decent tyres.
i can get pro racer 1's just in budget but then they will look way to small.

Why then do sportive models of a series have bigger wheels than the standard versions?
Why then do most manufacturers tend to increase standard wheel sizes?

Jochen

to make the cars look nicer! most cars handle worse when they have the larger option wheels.
look at the e46 m3 the 19" ruin the handling compared to the standard 18" wheels. if you had 17" wheels it would handle even better but it would look cack.

Fashion.

Racers in touring cars also have big wheels to fit the massive brakes and that makes people think that big wheels are faster and look cool.

In F1 they have carbon brakes so only have 14" wheels and very high profile tyres but you can't really make your road car look like an F1 without looking like a complete tit

I remember posting on the forum back in 2001 about wheel weight and how it would effect performance, it's no different now and Nigel is absolutely right !

If you go for 18"s you need to aim for a wheel as light as of lighter than standard or the increase in unsprung weight will only make the handling worse.

My 18"s are the same weight as a standard 16" wheel but the 35 profile tyres are never going to absorb road surface imperfections like a standard 50 profile tyre can, I have a much reduced unsprung weight with coilovers but I can still read braille through the steering wheel if I drive over it

well i have offered them all up and the fit. they need 15mm and 10 mm spacers and guess whats come up in the sale section at a good price!
preoblem now is the fact they look so good on the car i didn't want to put the ugly standard ones back on. i know its going to aftect the handling and bumps as it did in my last car they where fitted on but i honestly didn't notice really any handling differance and i know the theroy behind it but im wondering how bad it can be?

i don't drive that fast most the time and its mainly motorway driving and i don't like the standard wheels one bit and they need a refurb quite badly. can i put up with having harsher suspesion and lose a bit of handling for much better looks?

anyone swapped from standard to larger 18's that wheren't ultra light and wished they really hadn't?

On my old coupe (God rest her soul) I went from standard wheels to not particularly good or light 18 inch wheels.

They were both on Goodyear Eagle F1's. 205/50/R16's and 225/40/R18's.

The suspension was standard and not in as new condition.

Handling wise i loved it, with the reduced profile and increased contact area the turn in was sharper and the top line levels of grap were increased. The balance remained the same but you could push it further and faster through the bends.

Yes you could feel more bumps but i dont think it was a significant amount more. This is why i went for the 40 profile and not the 35 so that there was that little bit more tyre.

The only main downside in my opinion was dry traction. On the 16's i could easily catch it coming on boost in first gear and it used to bite in easily in 2nd with stage one mods. However on the 18's combined with a quick launch first disappeared into uncontrollable wheel spin and if pushed and not allowed for then it was pretty easy to break traction in 2nd gear.

On the plus side however it made my speedo exactly spot on. According to the sat nav. Whereas on the standard wheels and tyres it was about 4/5 mph out at 60mph.

Plus...i think she looked beautiful. But then i am biased hehe

did you notice any perforance loss?
i think i am going to just put them on and if i don't like them i am sure there are plenty of people who will buy brand new wheels pretty much with spacers and bolts.

oh also have you got any pics hillbilly?
i just thought the wheels i have look amazing and never seen them on a coop before or really many cars full stop so should be nice

At the end of the day its your choice. I know my car got more looks on the 18 inch wheels and i think it looked great with the wheels filling the arches.
To be honest i dont think i noticed any performance difference but like i said it was a little harder to drive due to the trouble putting the power down on the road.
But if anything my fuel bill went down
Some pictures:
16 inch



18 inch

I wondered about this too, I think you know what you mean but haven't typed it out right, the larger diameter the wheel, the lower the profile should be in order to result in the same rolling radius and therefore maintain the same speedo reading. There are quite a few tyre-selling websites with rolling radius calculators that will recommend tyre sizes etc. when going up a size in diameter. Width would be a different matter.

The issue with standard wheels, from one point of view, is that they tend to look a bit lost in the arches IMVHO. One point to bear in mind is that lowering the car does make the standard wheels look a lot better. I know when I saw Taffy's Sprinty when he came over one time, it looked REET nice (lol) but just had some bodykit parts (to draw the line down a bit) and lowered on coilovers. So IMVHO, standard wheels can look minty given the chance.

i am sure the standard wheels can look nice buti feel they need to be a different colour on a red car and then need spacers to move them out the arche a bit and then they need lot of lowering and the coilovers would have helped. i think a 30-40 mm drop stillgive to much of a gap between arch and wheel.

when ever i have swaped wheels i hve only noticed differece in harshness but alot of people complain about the rough ride on here. i will just have to see what its like.