I CU2 Posted December 25, 2013 Share Posted December 25, 2013 Hi guys, Can anyone tell me what tyre size to use if I were to upgrade my stock IS250 wheels (235/35/17 front and 245/35/17 backs) to ISF wheels? I'm really noob at this and want it to be legal without rubbing. The car is stock btw!Thanks and Merry Christmas to all :) Quote Link to comment Share on other sites More sharing options...
Lexus Nerd Posted December 25, 2013 Share Posted December 25, 2013 Stock size is 225/40R19 front, 255/35R19 rear. Perhaps some of the F owners may be able to advise on other possible sizes ...? Quote Link to comment Share on other sites More sharing options...
I CU2 Posted December 25, 2013 Author Share Posted December 25, 2013 I've read that 225/35/19 fronts and 255/35/19 rears were recommended by people on Clublexus - do you think that match-up would be legal? Quote Link to comment Share on other sites More sharing options...
Tony1234 Posted December 25, 2013 Share Posted December 25, 2013 Legally you can go 2"over standard size rims so 19s would be legal.Also i think a variation of + or - 5% in rolling diameter is allowed over standard.Correct me if i'm wrong!.I reckon your best option would be 18s.Looks good and decent rubber is still a reasonable price.Also the crap roads we have to put up with particularly in Sydney.My car has,i think the F sport rims on it which are front 225/40/18 rear 255/40/18.For ride,looks and handling i think this is a good combo. Quote Link to comment Share on other sites More sharing options...
Lexykid Posted December 26, 2013 Share Posted December 26, 2013 I have recently upgraded to ISF wheels with 225/35/19 at the front and 245/35/19 at the rears. Slight rubbing at the front when turning corners but nothing major to worry about. Ride and handling are no problems, however best thin I like, it makes the car look good. Just gotta get it lowered a little Quote Link to comment Share on other sites More sharing options...
Lexus Nerd Posted December 26, 2013 Share Posted December 26, 2013 ... want it to be legal without rubbing. The car is stock btw! Here's some information I learned after visiting the Website for Transport and Main Roads, Queensland. The last line will be interesting to anyone who has considered using IS F wheels on an IS 250/IS 350. Although each state determines what modifications are allowed on vehicles registered in that state, light vehicle modifications are generally guided by the National Code of Practice for Light Vehicle Construction and Modification (NCOP). Section LS deals with tyres, rims, suspension and steering. There are certain basic modifications allowed without certification, provided that the vehicle continues to meet Australian Design Rules, "the in-service provisions of the [Australian Vehicle Standards Rules] and rules found within the NCOP. I will paraphrase some of the key rules here - for more information, refer to the NCOP: No scrubbing allowed. When testing for scrubbing on a 5-seater sedan, you must load it with 415 kg of weight. The diameter of the tyre must not be more than 15 mm larger "than that of any tyre designated by the vehicle manufacturer for that model." Stock IS F tyres would be much too large at the front, even if your IS 250 manual/tyre placard suggested sizes for 18" wheels as used on IS 250 Sports/F Sport. However, the CL recommendation of 225/35R19 and 255/35R19 would be OK. There are rules regarding maximum increase in tyre width and diameter, but not aspect ratio. But aspect ratio is a function of diameter and width anyway. As long as you meet diameter and width requirements, and the aspect ratio of the fronts don't differ to the rears by any more than 10, you're fine. In short, using 225/35 instead of 225/40 at the front is OK. "When converting a passenger car’s wheels and tyres to those fitted to a manufacturer’s variant or high performance version of that model, the matching suspension components such as springs, shock absorbers and sway bars from the high performance model must also be used." This might suggest that an IS 250 fitted with IS F wheels must also be fitted with IS F suspension. You could argue that this rule doesn't apply, since you're only fitting "IS F wheels", and only two out of four "IS F tyres". But I'm not a lawyer, and I'm not going to offer legal advice on this matter. :-) Quote Link to comment Share on other sites More sharing options...
I CU2 Posted December 28, 2013 Author Share Posted December 28, 2013 Thanks Lexus Nerd! Decided to avoid them for now - seemed a bit complicated and expensive after new tyres needed to be put on as well. Quote Link to comment Share on other sites More sharing options...
LEX055 Posted January 22, 2014 Share Posted January 22, 2014 Im running 225/35 at the front and 255/35 at the back with no issues Quote Link to comment Share on other sites More sharing options...
kp_april Posted May 5, 2014 Share Posted May 5, 2014 Recently just had this setup but will changed the tyre to 235 soon. Front 245 35 R19 Rear 245 35 R19 Lowered with Eibach Prokit Rear has a lot of clearance but front rub a little towards the inner plastic cover when turning. Heat gun and a little pressing on the black plastic cover sort the rubbing issue. Quote Link to comment Share on other sites More sharing options...
Nahteno Posted August 24, 2014 Share Posted August 24, 2014 Hey Guys, I am looking at putting these on my IS250 , they stat its only a 8inch rim. http://www.ebay.com.au/itm/lexus-ISF-STYLE-WHEELS-IN-19INCH-TO-SUIT-ALL-MODELS-LEXIS-INCLUDING-IS250-IS200/141168464786?_trksid=p5411.c100167.m2940&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140131123730%26meid%3D5a5e93a3652c4f3f8549e7b139dc8712%26pid%3D100167%26prg%3D20140131123730%26rk%3D1%26rkt%3D15%26sd%3D231148553670 i was hoping to put 225/35/19 on front and 255/35/19 on rear, what are your thoughts on if it will fit. Quote Link to comment Share on other sites More sharing options...
ilv1004s Posted August 24, 2014 Share Posted August 24, 2014 they will fit Quote Link to comment Share on other sites More sharing options...
Nahteno Posted August 24, 2014 Share Posted August 24, 2014 Cheers thanks, can i ask why do people run a lower profile on the back. I seem to see alot of people running 225/35/19 front and 275/30/19 rear. is it due to the side wall ? or just looks ? Thanks again Quote Link to comment Share on other sites More sharing options...
Spec Posted August 25, 2014 Share Posted August 25, 2014 Cheers thanks, can i ask why do people run a lower profile on the back. I seem to see alot of people running 225/35/19 front and 275/30/19 rear. is it due to the side wall ? or just looks ? Thanks again The 30's are not actually lower profile than 35. Remember that the Profile number (middle one) is actually a percentage, not an actual width. For a 225/35/19 - The tire's width is 225mm, the profile (cushon or tyre height Edit: or sidewall)) is 35% of 225 which is 78.75mm. For a 275/30/19 - the profile works out to 82.5mm, it will be higher than the fronts. Quote Link to comment Share on other sites More sharing options...
Nahteno Posted August 25, 2014 Share Posted August 25, 2014 Ok thanks heaps, so I should be looking at going small profile on the back than to keep the over all Diameter close to the same. Quote Link to comment Share on other sites More sharing options...
Spec Posted August 26, 2014 Share Posted August 26, 2014 Ok thanks heaps, so I should be looking at going small profile on the back than to keep the over all Diameter close to the same. As long as you're comparing it to the correct pair. i.e if you're increasing the rim dia on the front, the tyre profile will get lower, same for the rear tyres. Just don't compare the profile between front and rear :P What's your current setup ? Quote Link to comment Share on other sites More sharing options...
Nahteno Posted August 27, 2014 Share Posted August 27, 2014 Cheers thanks again. currently have 205/55/16 front and back just standard 2007 Quote Link to comment Share on other sites More sharing options...
Spec Posted August 28, 2014 Share Posted August 28, 2014 So, on the front's if you're increasing to 17 inch, then you should look for 225/45/R17 - which will result in a -0.38% error. or for 18 - 245/35/R18 (+0.51% error) or for 19 - 255/30/R19 (-0.59% error) Probably worth searching these forums as well for Tyre size recommendations as some of these sizes may require rolled fenders or it will scrub, maybe illegal as well. Quote Link to comment Share on other sites More sharing options...
Nahteno Posted August 28, 2014 Share Posted August 28, 2014 I currently looking at some 18 and some 19, just waiting on a couple of places to email me back. with the 18s thinking of going 225/40R18 Front and 255/35R18 Rear. Thanks again for all the info Quote Link to comment Share on other sites More sharing options...
ldc Posted August 28, 2014 Share Posted August 28, 2014 225/45/18 and 255/40/18 would be better match imo. Speedo won't be out at all. Quote Link to comment Share on other sites More sharing options...
Nahteno Posted August 28, 2014 Share Posted August 28, 2014 225/45/18 and 255/40/18 would be better match imo. Speedo won't be out at all. oh, I was on a tyre size calculator website. and it shows Tyre Overall Tyre Diameter 205/55R16 632 225/40R18 637 225/45R18 660 255/35R18 636 255/40R18 661 Unless the website ive been using is wrong ? Quote Link to comment Share on other sites More sharing options...
ldc Posted August 29, 2014 Share Posted August 29, 2014 If you want to fill the gap more get 45 and 40. Quote Link to comment Share on other sites More sharing options...
ilv1004s Posted August 31, 2014 Share Posted August 31, 2014 Go with oem tyre specs U wont go wrong Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.