Falken RT615 225/40/18 reinforced - best PSI?

[Mid_Life_Crisis]

Falken RT615 225/40/18 reinforced - best PSI?

These particular tires are supposed to be 6 psi higher than regular sidewall tires. Has anybody run this size for an extended length of time on an MS3 or similar weight vehicle? What psi provides an even wear pattern and good, predictable handling? If you think it matters, I have mine on 8 inch wide rims.

 

[BSTD3]

Falken RT615 225/40/18 reinforced - best PSI?

These particular tires are supposed to be 6 psi higher than regular sidewall tires. Has anybody run this size for an extended length of time on an MS3 or similar weight vehicle? What psi provides an even wear pattern and good, predictable handling? If you think it matters, I have mine on 8 inch wide rims.

I'm running mine at 31PSI with no problems.

 

[Saitech]

Chalking the tires where tread meets the sidewall might give you a good idea how much psi to run. I run 34/32 cold for daily driving.

 

[Mid_Life_Crisis]

Chalking the tires where tread meets the sidewall might give you a good idea how much psi to run. I run 34/32 cold for daily driving.

Which is what the regular tires were at. According to Falken's website, these should be 6 psi higher, which would mean 40/38, which just sounds like they might as well be solid rubber. Ouch, can you say stiff?

 

[Saitech]

Is the 6psi during daily driving? They might be talking about competitive racing. Because I have to run 38-39 in the fronts for autox so I don't ride on the sidewalls.

 

[Mid_Life_Crisis]

Is the 6psi during daily driving? They might be talking about competitive racing. Because I have to run 38-39 in the fronts for autox so I don't ride on the sidewalls.

Quote from the Falken site:

Note: "Reinforced" tires require 6 psi added to carry the same loads as "standard" tires.

 

[fasteract]

I have found that the 615's don't tolerate heat as well as some so I run them at a higher inflation...I find that the fronts cold at 40 psi will show 44 psi when run aggressively which suggests they are happy here...a 10% pressure increase when hot seems to be the suggested norm. Overall the grip seems to deteriorate less when tires are on the "overinflated" side of the curve rather than the opposite.

 

[Mid_Life_Crisis]

I found a reference on Falken's website. Bear in mind that different sizes have different load ratings, but my tires, 225/40/18 have a load rating of 92. For reinforced tires with that rating on an MS3, Falken recommends 41 front and 39 rear cold.

 

[BSTD3]

41psi and 39psi seem WAY too high. That would be like riding on bricks if the pressure was that high. I adjusted mine to 32PSI (up from 31) and the car rides great and sticks like glue...

 

[MSPYOUNGERS38]

i would run 32, 33 psi and you should have no problems at all.

 

[Mid_Life_Crisis]

Quote from the Falken site:

Note: "Reinforced" tires require 6 psi added to carry the same loads as "standard" tires.

If you have the same tires I do and want them to hold up, I would listen to the manufacturer guys.

 

[BSTD3]

I've had a set of these tires on my 04 RX-8 running at 32PSI and they lasted well over 25K. I know this tire is not very long lasting, but I can't see running at 40 or so PSI without throwing the ride and handling out the winder...

 

[happy and angry]

Yea, tire manufacturers, engineers, what the hell do they know, AMIRITE?

 

[bacarl]

Haha, sometimes you wonder. But the more you research just exactly how much R&D must go into a vehicle suspension (which very much includes tire pressure), the more you can appreciate what they do. It's an unbelievably, rediculously complicated system!

Mid_Life, I just got my Falken 452s mounted, and am running them at F34 R33 for the time being, but it's an experimental process. Perhaps start at the manf. recommendations, then give/take a few pounds to see how you prefer it. Curious: why would reinforced tires require extra pressure? Seeing as how the sidewall ought to support more weight than on standard tires, shouldn't the required pressure be lower?

 

[Mid_Life_Crisis]

Curious: why would reinforced tires require extra pressure? Seeing as how the sidewall ought to support more weight than on standard tires, shouldn't the required pressure be lower?

Sounds contrary to simple logic to me, too, but I double checked the charts on the website, and sure enough, they call for higher pressures. In fact, for the weight of an MS3, for tires like these (and it varies by size as well as design) they recommend seven more psi per tire than the factory shoes.
Unless the reinforcing isn't in the sidewalls...

 

[bacarl]

Unless the reinforcing isn't in the sidewalls...

Could be... I'd be interested to find out. If it is the sidewall that's reinforced, have you noticed a change in torque steer with these tires? I'm on a quest for torque steer / suspension geometry knowledge and Wiki states to "Employ the use of a tire with proper sidewall ply design, mitigating the sidewall deformation" as a way to reduce torque-steer.

I'm just curious, as my torque steer went through the roof when I installed my Falkens (452s not 615s). I'm thinking it could be the fact that my new wheels altered the car's scrub radius, or it could just be a characteristic of these tires in particular.

 

[happy and angry]

Of course they affected torque steer, they are extremely grippy tires. Small alterations to scrub radius should produce small changes in the dynamics of the vehicle, so I'd attribute the increase in torque steer to sheer grip provided by the new tires. The more your front end can grab onto the road, the more power you can put down without tire slippage, which can enhance torque steer quite a bit.

Haha, sometimes you wonder. But the more you research just exactly how much R&D must go into a vehicle suspension (which very much includes tire pressure), the more you can appreciate what they do. It's an unbelievably, rediculously complicated system!

(I know, I was being sarcastic, what with everyone and their mother saying "HO HO, FALKEN SAYS YOU NEED MORE PSI BUT WHAT DO THEY KNOW? 32 IS FINE, I'M RUNNING IT RIGHT NOW!")

 

[Mid_Life_Crisis]

I'm just curious, as my torque steer went through the roof when I installed my Falkens (452s not 615s). I'm thinking it could be the fact that my new wheels altered the car's scrub radius, or it could just be a characteristic of these tires in particular.

I can't really say, as I put in Cobb springs and went with rims that are an inch wider than stock all at the same time. The offset is almost identical to stock at 50, which in theory should minimize any affect of rim change on torque steer.
I can say that (possibly due to the springs controlling the wheels better) torque steer appears to have been significantly reduced, although I haven't launched 1/4 mile hard yet, just pulled briskly (okay very briskly) away from some select stoplights.

 

[ericrapp]

My car has more grabbiness out of the rough, slower turns with throttle. Need the suspension upgrades, I do. I have not played with tire pressure yet.They are still at 34/32 from Element. Having performance tires really is good fun imo

 

[Mid_Life_Crisis]

During lunch I finally got to a shop with an air supply and set the tires to 41/39 as the Falken site said to. The difference in ride comfort? Zip, zilch, zero, nada damn thing. I can't feel any difference in the ride. The only thing I did notice that was different is that the car changes direction like it is supposed to. I had thought I screwed something up with the caster when I swapped the springs up front, but all along it was soft tires that took away the turning responsiveness.