Does the offset make a big difference? The offset on the wheel I want is 42. Tirerack says as long as its within 35-40 your safe. so is that 2 points going to make enough difference in rubbing? I also have an Eibach 1.25 lowering kit going on. this is a 1st Gen GS. in the front wheelwell there is some kind of arm that is pretty close to the wheel. So I guess, is there a huge difference in the size from a 245 to a 235. The 245 would look way better I think. what do you think?

Thanks
Mike

 

I guess I don't know your rim sizes, but my offsets are 44 I think. 8.5f, 9.5r. Of course it depends on the rim style as well.

 

Mike,

my first lex was the one you have right now, and i do vaguely remember something in the front that limits the wheel upsizing.

i also just checked tirerack's interactive fittment chart, and it is giving me 225/50/17 i am kind of confused right now as to the correct upsizing for you.
based on my calculation:

215/60/60 26.157" (overall height)
225/50/17 25.858
235/45/17 25.327 too small
245/45/17 25.681

since you have lowered the car, the best LOOK would be 245/45/17. do the followings:

1.call tirerack again tomorrow and ask them about 245/45/17

2.is there anyway you can put the wheel on the car for test fit? +42 for offset should be fine. but trying it on would be the best solution.

the bottom line: though 245 looks better, for safety issue, stay w/235s. but do the above first.

let me know how it goes.

william

 

I called the rim manufacture, and they recommended another company in there area. I was going to go with discounttiredirect. With them I saved $38 a wheel, and $6 a tire. The following day, I called to place my order, he recommended the 245/45-17, and guaranteed them to fit. I had the springs installed, it looks better, and the ride isn't that bad. I hope the wheels fit ok.
Thanks for the advice
Mike

 

Here is a very useful link to a fitment calculator I use. You just type in the startingn tire size you want to compare other size tires to and click calculate. Pretty slick.

Not sure if it will help here or not...

Tire Size Information

 

That site is great, I found it here a couple months ago, Ive been using it to find the correct size. Thanks

Here are the numbers for my old, and new.


Specification Sidewall Radius Diameter Circumference Revolutions Difference

215/60-16 5.1 in 13.1 in 26.2 in 82.2 in 771 / mile 0.0%

245/45-17 4.3 in 12.8 in 25.7 in 80.7 in 785 / mile -1.8%

Is the diameter the most important? Everything seems pretty close. The 245/45-17's are the closest size to my originals. So I dont think there should be a problem.

Mike

 

Hey Bit? How will I know what the correct offset is when I choose a wheel? Im considering 20's in the very near future. The wheel Im considering will be 8" front and a 9" rear. My idea for tires is 245/35/20F and 275/30/20R. How do I determine a good offset to make SURE the tires dont rub on the inside or outside, and also to give the car a stout look? Thanks, Tiny

 

Tiny,

if you do not mind me giving a few pointers:

for 98 and on, as long as you stay w/+35 to +45 offset, you should be fine. w/20s , in the sizes you listed, you have the correct tyre size.

i would look into 8.5+9.5, or 8.5+10 if i were you.

will

 

Thanks for the feedback gs4will, one last Q?
If the 20's I want are only available in 8" front and 9" rear, will the 275 be fine on the 9" rear rim? The reason I ask is because after looking at the web-sites of numerous tire manufacturers, they ALL say that the correct fitment for the 275 tire would be a minimum of a 9.5" rim, to a max of 10.5". But, I have seen 275's on 9" rims on more than one occasion, and it looked awesome.(and the tire wasnt hanging over the rim very much at all) I want to be sure that I am in no way sacrificing my safety somehow by going with a 275 on a 9"rim.
Finally, after looking at every tire manufacturer that I could think of, the ONLY one who had a 265 in a 20" high performance tire was Yokahama(AVS sport). That is the ugliest tire Ive ever seen!!!

 

tiny,

i checked a few major tyre brands for you, and only Pirelli P0 has the 245/275 you are looking for. Nittos might have them too since that is the brand Manaray has on his gs.

toyo has the 245/35/20, but not 275s.

for fittment: 245 takes a min of 8"
275 9"

i just look at the Michelin guide, and those are the # they gave me. call tirerack tomorrow and ask them for sure.

will

 

Thanks much, I will call them, but that makes me rest a little easier.....I currently have the 245F and 265R set-up on my 18" SSR's. I like the staggered look alot but would prefer to even go a little wider in the rear.....Youre right about the tire sizes, although, BFG g-force, Michelin Pilot and xgtz4, Yokahama AVS sport, and the Nitto extreme555 are all offered in the 245F, 275R set-up Im after. I am definitely getting the NITTO's when the time comes.....they are going to be 245/35/20, and 275/30/20. Nittos are a lower profile than the rest of the mfg's. (5mm on front and rear) and cheaper, but my car will still ride hire than it does now...here is the tire size translation:
current front: 245/40-18 3.9 in 12.9 in 25.7 in 80.8 in 784 / mile 0.0%
current rear: 265/35-18 3.7 in 12.7 in 25.3 in 79.5 in 797 / mile -1.6%
20" front: 245/35-20 3.4 in 13.4 in 26.8 in 84.0 in 754 / mile 4.0%
20"rear: 275/30-20 3.2 in 13.2 in 26.5 in 83.2 in 761 / mile 3.0%

Will, can you tell me if the overall height of my car will change based on the change in wheel DIAMETER, or is it based on the RADIUS?(area from the very center to the outermost edge of the tire=half the diameter) It is the radius right? If my thinking is correct, I will be raising my car exactly 1/2 inch all the way around? Also, how do you know how to choose the exact offset that will not make the wheel sit too far inside the wheel-well, and the offset that will not cause it to stick out too much? We are dealing with MM's right? What offsets do you run?
Thanks a ton, Tiny

 

Tiny,

let me answer the best i can.

1.nittos are in general, a bit lower in profile #s. have you compare them to the xgtz4 in prices? both are good.

2.when you compare the overall height, the most important factor is the DIAMETER, imo( several tyre guys from the factory and retail level told me this also). plus, you should always based your comapro on the ORIGINAL tyre size, the factory 16s, not what you have done on the 18s.

factory orig.225/55/16 25.744"(overall diameter)
factory 17" up 235/45/17 25.327"-too small, imo
better 245/45/17 25.681"

i think the factory tried to save some $$$ so they went w/235/45/17.

3. for 245/275 in 20s as you mentioned, the sizes are the ones people use, but the ~3% increase in overall diameter might cause a bit of rubbing from time to time. (i think manaray might have mentioned this too, if i remember correctly). hence, some choose to do a little fender lift to avoid this.

4. the higher the "+" number in MM in offset, the more the wheel spoke goes in towards the center(looking from outside of wheel towards the center). for example, on an identical wheel, toyota supraTT would take only +32 for the front, but the gs could take +42. why? because supra has that big break caliper that does not accept high offset- the wheel spoke might hit the calipers.
to choose the right offset, people usually refer to the wheel guide supplied by the wheel co. and the larger the wheel co., the better the guideline.

5.depends on wheel brands, i like to get +40 to +45 offsets for my wheels.

for more better, and detailed answers, try www.toyo.com

there is a toll free # that you can call for a copy of guidelines on wheel+tyre upgrading and issues relating to suspensions.

william

 

Will, thanks again, very helpful info.
If my intention is to go with the supraTT brakes just after getting the rims, what front offset will I need to be sure the rim will clear the caliper????? Also, when you say that you like to get +40 to +45 offsets for your wheels, how did you decide this? I currently have 18's with +35 on my 8" fronts and +45 on 9" rears, will this be ideal for 20's as well? When a wheel manufacturer says that the available offset is from +35 to +45, does this mean you can request any MM offset within that entire 10MM range? Tiny

 

tiny,

you have the same intention/plan as i do. so when you consider rims, ask for the supra TT offset for the front. usually this means between -30-38 , i think.
i do not know what brands/model you are considering. but for well known rims from large co. such as HRE, volk, RAYS, they all have specific guidelines and fittment offset designed for each car model.

when say i like to get between +40-45 because gs will accept any offset # in this range without any prob. plus i have done many research and looked at many wheel designs that I like, and most of these rims have offset designated for the gs within that range.

when a wheel co has, say, +35-+45 offset range, they may/may not have the offsets in each MM increment. but yes, they prob offer 3-5 diff offset in that 10MM range. for the custom made wheels, like the expensive HREs, i believe you can speicify any offset you want, for a price. therefore, it all depends on which wheel co you are dealing with.

for 20x8. (+35) x9(+45) should be fine. are they the same design as you 18s? do you mind telling me which wheel model interest you?

william

 

The wheel that I am considering is a Binno(division of Borbet), model B-930. You can peep at it on www.binnocustomwheels.com. There is also a set for sale in the classifieds section right now but they are not staggered and I dont like chrome. That is where I saw them for the first time. They have a similar shape to the SSR. My SSR has about two inches of clearance between the spoke and the caliper, thats why I felt I would be safe for the Supra TT caliper using the same offsets. The spoke on the Binno actually looks to curve more which should supply even more clearance fo the Supra TT caliper. I have ALWAYS liked the more simple rim designs similar to the SSR Integrals I have now. (simple sporty 5-spoke w/or w/out rivets) I like the fact that as far as I can tell, they arent a knock off of another wheel, like is so often the case with the less expensive one piece cast rims. I also doubt that I will have more than a couple of choices for offsets.
The rim is a one-piece cast not forged so I suppose Im sacrificing strength and weight as well. But, the longer Ive had my GS, and the more Ive looked at my 18's, the more i feel it requires 20's to look at home. The GS is so bulky, 18's are looking like training wheels....Tiny