nudderGS400

Good idea bad idea , thoughts?

According to the specs link on tirerack, 245/50's work on a measured rim width of 7.5" which is what stock (98+) GS400s come with. I think!? Too much bulge? Sidewall roll? Clearence?

Your thoughts are appreciated.

nudderGS400

RON430

I have been looking at the 245/50-16 as well but I thought that I would have to get rims. I thought the 245 really wanted eight or eight and a half inch width. Anybody know for sure?

nudderGS400

Her is the link for tirerack for the Kuhmo Ecsta 712.

http://www.tirerack.com/tires/Spec.j...CSTA+Supra+712

The column labeled Measuerd Rim Width is defined by them as...




Measuring Rim Width
The measuring rim width is the industry standardized rim width upon which the tire must be mounted in order to confirm it meets its dimensional targets. Because the width of the rim will influence the width of the tire, a standard rim width for every tire size is assigned and must be used. This standardized measuring rim width allows all of the tires produced around the world to meet the same dimensional standards and therefore, be equivalent with regards to their physical size. The measuring rim width is sometimes referred to as the tire's "design rim width".

The assigned measuring rim width changes with the tire size's section width and with the tire size's aspect ratio. As tire section width increases, the measuring rim width increases proportionately in 1/2" increments. Therefore, relatively narrow wheel widths are assigned for smaller tires while wider wheel widths are assigned for larger tires.

Tire Size Measuring
Rim Width

P175/75R14 5.0"
P195/75R15 5.5"
P215/75R15 6.0"
P235/75R15 6.5"

Additionally, relatively "narrow" measuring wheel widths are assigned for taller profile tires (75-series sizes) which graduate in 1/2" increments to the wider wheel widths assigned for lower profile tires (40-series sizes)


Tire Size Measuring
Rim Width

P225/75R15 6.0"
P225/70R15 6.5"
P225/65R16 6.5"
P225/60R15 6.5"
P225/55R15 7.0"
P225/50R15 7.0"
P225/45R17 7.5"
P225/40R18 8.0"

Section Width

chowder

based on my recent tire purchasing experience, the 245 width won't be a problem. if you don't want to skew your gauges too much, just pay attention to overall diameter.
the real reason i'm chiming in though is b/c i tried those 712s. on the tirerack user reviews, you can find mine on the 2nd page; it's the first gs4 one you get to.

Vlad_Stein

You should check allowed / reccomended rim widths from the tire manufacturer you are considering. From my research (at TireRack), OEM 16'' wheels are within specs to accept 245s.

245/50/16 is a good choice, because it has almost the same diameter as the original spec 16'' tire, so you will not have any odometer problems or effective gearing changes.

The only thing is, because the tires are wider and rims are the same, the tire is going to be a bit "squishier", as opposed to a tire that is "pulled over" a wider rim. How much that would affect handling, I don't know.

nudderGS400

The story progresses, I called tirerack today and spoke to one of the salesguys and he recommended 235/55 instead of the 245/50. Now I'm really confused... He had some convoluted explanation about how that would not throw of the speedo as much. My brain is still tellin me 245s.

RON430

I think your brain is right. All the dimensions I have checked show that the 245/50/16 is about an ideal swap for the stock 225/55-16.

nudderGS400

So, now the question is what tire? Anybody have experience with relative differences for; Nitto 450, Kuhmo 712, Falken Zeix, Dunlop 5000, Yoko DB's?

My priorities are 1- hydroplaning, 2- hydroplaning, 3- wear. I assume they are all about even on performance in general.

RON430

While I am no longer a big fan of them if your priorities are hydroplaning, hydroplaning, and wear, you want an open tread pattern with a hard rubber. Sounds like a Michelin.

nudderGS400

OK, I did it.

Put on 245/50 ZR 16's and I am very happy with them.

Yokohama AVS dB's, ride is softer, which is OK with me after making it stiffer with EIbach/Bilstein. Handling is much improved, and they look good.

Almost went with the Dunlop SP5000, thought these would last longer, and of course there is that hydroplane rating on Tirerack that I liked.

They do bulge on the sides a little more than I would like; however, they don't feel mushy and don't float on straightaways or follow the truck grooves excessively.

For me, it was the right choice.

RON430

nudderGS400 - So, did you use the stock rims? We don't have a good place to post updates but I would be interested to hear what you think of the dbs after several thousand miles. Almost any tire is quiet new but the question is how they do after a bunch of miles which is, no secret, my problem with Michelins. The Dunlop might be a good tire but as far as I am concerned, all it does is give us more choice which ultimately is a good thing. I expect you have exactly what I will do on my mine once the Michelins wear out. Gs4will posted that Yokohama was coming out with a new model that would be between the db and the AVS sport but I haven't seen them yet. Still very impressed with the db on my wife's Maxima and absolutely no unusual wear at all with almost 10K on them. Once again, thanks for the original thread, I think this is a great option for a bigger footprint without some of the various hassles of bigger rims.

nudderGS400

Ron430 - I'll let you know how they hold up, have about 2000 miles on them so far (2 weeks) and they seem OK.

BTW - yes they are on the stock 16 inch rims.

RON430

Cool - thanks.

Murph

NudderGS400

Please post a pic or 3 as I am also curious how they look.
Thanks

Murph

tri lexus

i put goodyear 245/50/16 eagle f1's on my gs but 20K miles later, noticed SEVERE wear on inside tread (almost bald). asked the dealer who recommended against something that wide, claiming the wheel could not support the width. i have subsequently gone to michelin 225/55/16 pilots since. much smoother ride.