risc4

Hi guys. I've read a lot of old threads and there seem to be a lot of different feelings about low profile tires. Any new opinions based on your experiences? I own an SC400 in New England where there are some potholes and a ton of frost heaves on our roads year-round due to our winters. Stock tires are 225/55/16.

I would LOVE to go to 255/40/18f and 275/35/18r for the improved look and traction (for a likely future torque converter and NOS). But can some of you in a similar circumstance to mine comment if you have switched and gotten a noticeably harsher ride, or have you bent a rim from bad roads? I will accept a slightly worse ride, but I don't want one considerably worse.

Or am I better off going 255/45/17 on all four wheels? Though this would be a smaller wheel than 18, I am willing to pay good $$ for a hot-looking set, so I'm not concerned --anything is an upgrade over these stock wheels, the only thing I hate about my SC400.

Thank you all for your thoughts!

lex400sc

Go with 18s, you will be much happier than upgrading to just 17s. The harshness of the ride really depends on what tires you choose to wrap around your wheels and how wide. I haven't played with enough tire brands to give you good advise on that, but I'm sure others can. One tire I don't like are the stock Bridgestone tires. Harsh *** ride, even on 16s. As long as you buy quality wheels and don't drive abusively, you won't have to worry about bending rims.

SRQ400

I agree with lex400sc that 18” would look the best but I put 17” with 255/45 on mine for the same concerns as yours. As well as prices and availability of tires. But that’s just my take!

risc4

lex400sc: I went to your site (very nice) and it says you have 17s. Did you switch to 18? How were/are the 45 series? I assume they rode well, not too harsh, given your previous reply?

srq400: I wasn't sure--do the 255/45/17 tires fit ok in the front? No rubbing?

Anyone else with experiences to share?

Lex Luthor

Fitting a 255 in the front will only work with certain offsets same for the 275's in the back (though that's usually not a problem in the back), be careful, 235's and 265's will work with almost anything +38 to +45 and more. You can fit monster rubber under these cars with the right wheels, so you may want to do alot of homework, lord knows I did. As far as ride quality, that's a subjective type of thing, but I find the ride to be very acceptable in an SC with 18's, as far as damaging them, that depends on how careful you are, but I haven't had a problem, and the roads here in NY look like Kosovo.

lex400sc

Yes I have 17s right now. I bought them for a good price and there really are leaps and bounds better than the stock wheels in design, strength, and sizing. But I bought them with the mind set that they are either going to be temporary wheels or winter/track wheels. I have my end goal set on 19s or 20s. Maybe 18s if the design is right and the lips are big. The first set of rear tires I bought for my 17s were 40-series. They look much better because they are thinner sidewall and match up evenly with the staggered fronts as well as the lowering springs. However, they were 3.5% smaller than stock diameter, and 45-series is less than 1% smaller, so 45-series tires are more accurate sizes. 255 tires are prety wide. I'd say that's the widest you want to go on the rear of a stock-powered SC400 for traction purposes. Anything wider may look better, but will slow your car down. The front tires don't need to be 255mm wide. They are the steering wheels, and IMO should be thinner than the rears. 225 is fine for those, 235 if you want, no more than 245 IMO.

henrynguyen

I got 40 series in the rear, looks good but ride like horse back . Go with 17, more choice than anything else.

risc4

Thanks guys...all of your answers helped out. I just need to weigh all the opinions together...

Anybody else have 35 or 40 series? Harsh ride on the bumpy roads or tolerable? In other words, if you had the girlfriend/wife/stuffy business person in your car, would they be complaining "I thought this was a Lexus? It rides like crap!!"?? Or would they not really notice?

BTW I have stock size Pirelli P6000s on my car and like them. Are their shorter sidewall performance tires good also?

wmulli

I've got the Bridgestone S03's. 225/40/18 on 18x9 up front and 285/35/18 on 18x10 on the rear. They are a bit harsher than stock, but well worth it for the added grip IMHO. In the summer at least! They freak out at the mere thought of snow!

I like your standard "will the stuffed suit think it rides like crap" LOL!! Well, it definately won't ride like a Lincoln! More like a porsche. That's a matter of opinion whether it's crap or not

You didn't mention what springs/shocks you have. They probably make a bigger difference than than wheel size.

risc4

wmulli,good point on suspension. I am stock now but I am also contemplating lowering it 1". How much extra harshness does a 1" lowering cause? It seems to be moderate according to other threads I have seen. Agreed?

I guess I want (impossibly) the best of both worlds. Quick (mid 13 sec 1/4 mile -- I have that plan figured out) , great looks & a non-abusing ride. But don't we all?

What intrigues me is that Mercedes has 35 series rubber on its 2003 $120k SL coupe. Many other new sports cars have 35 or 40. If 35s ran that rough, I can't imagine Mercedes torturing its pampered customers with a brutal-feeling ride. On the other hand, I read threads on this site and others how many enthusiasts complain about low-profile tires.

I need to just bite the $2000-3000 bullet and get new wheels/tires and see what happens! Decisions, decisions...

wmulli

Well, everything in life is a compromise If you want looks/better grip, you give up some cushyness

With that said, some low profile tires are better than others. Check Tire Rack for their tire reviews. I've found them pretty close in the past. Another thing that will help when going to bigger/lower tires is to get the lightest wheels you can. Unsprung weight seems to be the worst enemy of a smooth compliant ride.

And yes, lower springs will add to the stiffness simply due to the higher spring rate from reduced travel.

Also, I'm unconvinced that gas shocks give a better ride. I agree they handle better and don't fade like hydraulics, but the nicest rides I've had have all been on hydraulic shocks.

Well, that's all my wisdom about ride comfort Do your homework and good luck. Keep us informed of how things turn out for you!

aasc300

I am running 245/35/zr20 Nitto NT-555 Extreme ZR's with tokico blues and an eibach prokit 1" lowering kit. The cars sits perfect and the highway handling was greatly improved. Pot holes and pavements breaks will give you a little bit of a beating, but for the most part, I love the ride quality.