Lowered PSI for Comfort

[clindsay123]

Hi everyone,

I recently got a new set of wheels tires as I've been on a quest to find the sweet spot for daily driving in Los Angeles / durability in the Sierras and deserts of the southwest where rocks are plentiful.

I landed on 285 70 17 C rated Ko2s which came in at only 50 lbs per tire! My previous set were E rated Ko2s and I hated the jarring ride. I was disappointed to find that the C rated tires weren't much of an improvement in NVH, even at 35 PSI.

That said, today I lowered the PSI to 33 and they feel MUCH better. Seemed to have passed the chalk test as well.
I did notice there is a very small bulge at the bottom of tire (pictured below) and am curious if this is an issue at all. It's not too noticeable in person unless you look for it. America's Tire said it's totally fine but I don't trust them as they probably want to avoid me exchanging tires.

Thanks!

 

[Coin]

Looks normal to me.

 

[hoser]

If you were going by Toyota recommendations for load/pressure, you would run 36psi front, 39 psi in the rear. You certainly can run a few psi less day to day but I would run 36/39 or more when loaded up.

 

[clindsay123]

Looks normal to me.

Looks normal

Looks normal to me.

Thank you Coin, I know we are both suffering victims of the E rated tyranny

If you were going by Toyota recommendations for load/pressure, you would run 36psi front, 39 psi in the rear. You certainly can run a few psi less day to day but I would run 36/39 or more when loaded up.

ya I’ll definitely up it to 35+ when loaded

 

[x8o8drifter]

If you were going by Toyota recommendations for load/pressure, you would run 36psi front, 39 psi in the rear. You certainly can run a few psi less day to day but I would run 36/39 or more when loaded up.

Aren't even close to the stock tires so those numbers mean nothing.
Even switching brands can sometimes change what you should be running.

 

[hoser]

@x8o8drifter I converted the numbers, they do mean something.

 

[DuckLN]

50 lbs per tire is heavy. Been there done that. The 41 lbers ride much better and ive not had a flat yet.

 

[x8o8drifter]

@x8o8drifter I converted the numbers, they do mean something.

Corection: I meant IF you don't do anything to correct them.
Like 99.999% of people will do.

 

[clindsay123]

50 lbs per tire is heavy. Been there done that. The 41 lbers ride much better and ive not had a flat yet.

Considering the next lightest option is almost 60 lbs for this size / load rating, no these are not heavy. In fact, they are the lightest option available.

I’m sure the SL tires ride better, but no flats? What’s your use case?

 

[89BIGBLUE]

My 99 door card/sticker says 32 psi and 32 psi for the OEM 275/70R16.
WTH, I'll try it for a week and see if the 265/75R16 ko2s on it are cushier DD duty.

 

[89BIGBLUE]

So, after a week or so, and a 400 mile road trip, I'm surprised to say I did notice an increase in "comfort" with the tire pressure at all 4 corners at about 34Psi.
Average MPG on the return road trip tank of fuel was 16.7.
Will continue this pressure and observe.

 

[excessive]

ive always run 30-32 psi on my 100 for comfort, highly recommend if you have E rated K02

 

[clindsay123]

So, after a week or so, and a 400 mile road trip, I'm surprised to say I did notice an increase in "comfort" with the tire pressure at all 4 corners at about 34Psi.
Average MPG on the return road trip tank of fuel was 16.7.
Will continue this pressure and observe.

glad to hear you've benefited from lowering PSI. I've gone all the way down to 33 and not seeing significant changes.
Starting to think my suspension might need to be addressed.

 

[TexLexican]

Wasn’t 32psi the standard for any car up until about 10 years ago? They say you get greater fuel efficiency the higher the psi, but the tires don’t last as long.

 

[x8o8drifter]

Wasn’t 32psi the standard for any car up until about 10 years ago? They say you get greater fuel efficiency the higher the psi, but the tires don’t last as long.

No

 

[hoser]

Wasn’t 32psi the standard for any car up until about 10 years ago? They say you get greater fuel efficiency the higher the psi, but the tires don’t last as long.

Well, not a "Standard" but since 20+ years ago, vehicles have gotten generally heavier (due to safety standards) and speed ratings have gone up.... so those will affect recommended tire pressure. There was that whole Ford/Firestone case where everyone pointed fingers. In any case, in the end, they raised the tire pressure recommendation from like 26 psi to 30 psi. But those vehicle also didn't have any type of TPMS.... so people were probably running way less than 26 psi.

I do believe hyper-inflating your tires will decrease rolling resistance and thus increase fuel mileage but you are also reducing traction. There's a whole slew of factors why manufacturers suggest whichever tire pressure rating but certainly GVWR, safety, top speed, emergency handling, fuel mileage, etc..... all come into play.

 

[nissanh]

A tire with 6 ply rate can go down to 29 psi, however, a 10 ply rated should not run below 40 psi as the plies can crack internally. I was on 10 ply and hated the ride and switched to 6 ply and now on 29 psi on all corners.

 

[hoser]

My E-Load, LT-Floatation tires even show load tables down to 25psi. I don’t think it is a problem granted the pressure is appropriate for the load.