Premier 18" Wheels

[kelvin333]

Hi,

I'm new to LOC, but have really enjoyed members' helpful and friendly comments on the IS Hybrid.

I test drove the Luxury and was completely blown away by it - made my BMW 1series Sport seem rough, unrefined and very spartan.

I've ordered a Premier for March 1st delivery (can't wait)!! :hocus-pokus:

My concern is the 18" wheels, as the potholes in my area are really bad (Manchester).

Will the larger wheels thud and badly disturb the excellent ride?

Thanks

[powerkitten]

Well I have the18 inch wheels on my premier and from my experience the ride is superb. I did test drive a premier on 17 inch wheels, and can't recall much difference between the two.

[Roger Bill]

Hi Kelvin,

Congratulations. In January I'm hoping to order a Premier with the no-cost 17" wheel option because I share your concerns about ride quality. I haven't been able to compare ride quality with different wheel sizes in the new IS but experiments with my 2009 IS showed some, but not a dramatic, difference. Another advantage of the 17" option is the improvement in fuel consumption, according to figures in the brochure. Also I guess the wheels and tyres should be less susceptible to damage from hitting pot holes and presumably the tyres should be cheaper to replace. Finally because the front and rear 17" tyre sizes are the same they could be rotated to balance wear. Sorry I'm beginning to sound like a salesman so maybe I should end with the contrary point that 255 wide, lower profile 18" tyres should improve road holding.

[kelvin333]

Roger

Thanks for comprehensive answer.

Your point about better road holding is a strong one in favour, as we do not have council winter gritters on our avenue any more, and with the rear wheel drive, I really struggled with the snow and ice in my previous (2nd generation) IS.

[DJP]

I thought the wider the tyres the worse the grip in snow and ice? Probably something else I've got wrong lol.

[kelvin333]

Thanks David

I've checked on the net, and some say bigger/wider tyres are better on snow and ice, yet some contradict this.

Does anyone have a definitive answer please??

[Clearline]

I test drove the Premier and I went for the Luxury 17". I don't think I could tell the difference. The ride is very comfortable, I live in Manchester too!

[Wicksy]

Thanks David

I've checked on the net, and some say bigger/wider tyres are better on snow and ice, yet some contradict this.

Does anyone have a definitive answer please??

Thanks David

I've checked on the net, and some say bigger/wider tyres are better on snow and ice, yet some contradict this.

Does anyone have a definitive answer please??

DJP is correct, Kelvin, the wider, bigger the tyres, the less grip you will get. The smaller, skinnier tyres give the greatest amount, especially on rear wheel drive. Every Lexus I've had has been an absolute dog in the snow, winter tyres are a must.

[Roger Bill]

This page: http://www.ehow.com/about_6586564_wide-vs_-narrow-tires.html

contains a good explanation of the benefits of narrow tyres in snow & ice.

I got a used set of 16" wheels from an IS220d & was going to fit them with cold weather tyres assuming I could use them both on my 2009 IS250 and on the IS300h I'm hoping to order early next year. However, I've now been told the wheel stud pattern and/or the wheel offsets for 16" wheels on the IS2 and IS3 are different. Can anyone confirm whether the fitments are different?

[Silver Arrow]

For years and years Lexus have generally used the following:

Stud - 114.3 (which is common to a lot of Japanese cars)

Offset - ET 38 to 45 (get this wrong and either your tyres will rub the arches, or won't fit the rotors properly - you can get shims to adapt off eBay)

Bore - 60.1 (you can get adapters from eBay)

In fact my new shape MK4 GS250 is running the 18 inch MK3 GS SE-L rims (5 spokers) with winter tyres and no problems - they went straight on. I did have a set of GS MK2 300 Sport alloys that also fitted it - they were 18's. (114.3, ET45)

However, I believe (could be wrong) that the CT has moved away from this standard - and so it's a valid question - has the new IS changed too? You can easily look by taking a wheel off - the offset, rim width etc are usually embossed in the casting on the inside of the spokes, or you can use a mirror. I should have checked the IS300h I had (F Sport) with a dental mirror, but never got round to doing it.

Once you have the wheels, you can compare what tyre sizes you have and what you are changing to by following this GUIDE

[F Sport Marcus]

Wider tyres give less pressure on the road/snow/ice due to increased contact patch so therefore easier to spin.

Look at the WRC snow/ice tyres - they're skinny..

[CD69]

You guys are really worrying me now. Get my F-Sport a week tomorrow and as a company car I don't have the option of fitting Winter tyres. I know all RWD cars are rubbish on snow and ice but is the IS worse than the others? Had my current car, a C250 CDi Merc for 4 years and I've just about managed!

[DJP]

I don't think its any worse than any other, and maybe the extra weight of the batteries will help. As it's a new model I guess we won't know until the bad weather sets in.

[Roger Bill]

Hi Jonas, That's really useful info which prompted me to do some searching. Found this http://www.wheel-size.com/size/lexus/is/2014/ which, if correct, seems to suggest I could get winter tyres on my spare set of IS2 16" wheels and use them on the IS300h. The centre bore diameter is the only missing measurement. If the IS300h centre bore is different I suppose adaptors could work but I'm not sure it's a solution I'd be happy using.

[Silver Arrow]

Hi Jonas, That's really useful info which prompted me to do some searching. Found this http://www.wheel-size.com/size/lexus/is/2014/ which, if correct, seems to suggest I could get winter tyres on my spare set of IS2 16" wheels and use them on the IS300h. The centre bore diameter is the only missing measurement. If the IS300h centre bore is different I suppose adaptors could work but I'm not sure it's a solution I'd be happy using.

Yes you can, but….make sure you tell your insurance company, as not only will you be putting winters on, but of a different size too…...

2 things of importance:

1) The rolling circumference (which can affect your speedo)

2) The insurance company - what will they accept

And as far as the bore is concerned, do a good search on the internet/ebay, but I feel they won't have changed that, so they should go straight on

[F Sport Marcus]

I don't think its any worse than any other, and maybe the extra weight of the batteries will help. As it's a new model I guess we won't know until the bad weather sets in.

I reckon they'll be as hopeless as the rest of the rear wheel drive lot, especially the wider tyred ones. I changed my mind to the Lexus having chosen an Audi Quattro so the few days I'm slipping and sliding I'll just remember the financial benefits and dream of saving the planet!!

[Roger Bill]

http://www.club80-90syncro.co.uk/Syncro_website/TechnicalPages/TRC calculator.htm
This website contains a useful calculator which outputs circumference, speedometer deviation and "comfort" numbers. All the IS300h tyres circumferences are very close and so, relative to the 17", the speedometer deviations are all within +/-0.5 km/h.

The tyre suspension comfort values range from 0 (very bad) up to 10 (very good), depending on tyre shoulder height. The IS300h 16" tyre size has a comfort value of 6.5, whereas for the 17" it is 4.7 and for 18" tyres it is 2.8 and 2.9. Interesting, these figures suggest there should be a noticeable difference in ride comfort between the 3 wheel sizes.

[Silver Arrow]

I think modern cars are designed to handle well and provide a sporty drive - so the way to do that without electronics and AVS is a firm suspension. The firmer suspension you have, the more noticeable the effect of the tyres, as the rubber will bend and flex to help the suspension. The lower the profile of the tyre, then generally the higher the tyre pressures - and with rubber bands you're gonna get little flexing of the rubber = firmer ride.

As far as snow is concerned then as pointed out, the wider the tyres, the more likely they are of "sitting" on top of the snow as opposed to "cutting" through it and giving the rubber a chance to contact the tarmac below. As the tread fills up with snow, the worse it gets.

Lexus is no better or worse than BMW, MB etc when it comes to snow. And whilst a 4x4 is great for getting you going, with summer tyres it will be just as bad as a conventional car at stopping, especially if weighs over 2 tonnes. The new IS is a very heavy car - and so whilst the added weight of the batteries might help you to get going, it will be harder to stop. So I suspect winter tyres are a must!!