Hyundai Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
47 Posts
Discussion Starter · #1 ·
I recently put my winter tires on my 09 Santa Fe Limited, but I decided to downsize the rims from the 18" that it came with to 16" and go with 235/70R16 instead of the 235/60R18 they came with. My question is, what should the tire pressure be? I assume it would be different for this size of tire compared to the stock size. The sticker in my door sill says 30 psi front and rear, but that is for the 18's. What should the 16's be at?

Currently I have them all at 35 psi, but the front driver tire almost looks low to me. Thoughts?
 

·
Registered
Joined
·
2,550 Posts
The same!

Changing from 235/60x18 to 235/65x17 or 235/70x16 makes no difference to the size of the tyre contact patches nor the weight of the vehicle.
 

·
Registered
Joined
·
2,550 Posts
Our UK models have 33psi as recommended pressures but the tyres wear on their outer edges - increasing up to 36psi seems to even the wear better.

The harsh ride only occurs of the OE Kumho's - with decent Pirelli's on the ride is much better.
 

·
Registered
Joined
·
47 Posts
Discussion Starter · #7 ·
Interesting. I would have thought that the increase in the sidewall height would require a greater pressure to keep the tire where you want it as even at 25, They look like they squish out a bit.
 

·
Registered
Joined
·
1,803 Posts
Going by the door sticker is only good if the replacement tire and the OEM tire have the same max PSI when cold. Many replacement tires have different max PSIs Your new tire will have the max PSI on the sidewall, as long as you do not exceed that when cold you are fine. I find that on a tire with a max of 44PSI around 40 gives me the best wear. Lower than that and the tires wear on the outside edges, especially in fornt.

Check the sidewall of tire. manufacturers set the recommended amount on the sticker for a comfortable ride, not necessarily the best wear.
 

·
Registered
Joined
·
2,550 Posts
Interesting. I would have thought that the increase in the sidewall height would require a greater pressure to keep the tire where you want it as even at 25, They look like they squish out a bit.
There is no increase in sidewall height - 235/60x18, 235/65x17 and 235/70x16 all have the same sidewall height, near as makes no difference anyway.
 

·
Registered
Joined
·
2,550 Posts
40 psi on a Santa Fe for most tires will give it a twitchy steering feel and take out the center of the tire early.
Maximum tyre pressures moulded on tyre sidewalls are absolute maximums - most cars are specified with tyres that are best run at 50-70% of that.

As Canderson says, 40psi is way too high.
 

·
Registered
Joined
·
7,163 Posts
18 = 5.6"
17 = 6"
16 = 6.5"

So from one extreme to the other, it comes to just about 1" of additional sidewall. It's that 1" that has some owners hoping that a move from 18" to 16" will soften the ride, but I haven't seen that it really makes much of a difference if you stay apples-to-apples within a specific brand and design.
 

·
Registered
Joined
·
329 Posts
I don't know how many times I've seen the maximum pressure on the side wall used as the inflation pressure. Completely bogus and dangerous!
On the sidewall along with the max pressure is a statement about maximum load per tire. The maximum recommended pressure is what is required to support the maximum load rate of the tire which sometimes is 3 times the actual load exerted on the tire by a SF.
For example, there are truck tires that have a maximum pressure rating of 60 psi that are used on passenger cars. Would you inflate these tires to 60 psi? Of course not.
The dangerous part is where someone installs a 60 psi tire on a 45 psi rated rim. That is a disaster waiting to happen.
RANT OVER
 

·
Registered
Joined
·
329 Posts
Maximum tyre pressures moulded on tyre sidewalls are absolute maximums - most cars are specified with tyres that are best run at 50-70% of that.

As Canderson says, 40psi is way too high.
They are maximums based on the maximum load capacity which an SF will never reach (or shouldn't). Truck tires are used on the SF as well and they can have a rating of up to 60 psi. Nobody in their right mind would inflate a passenger car tire to that rating.
 
1 - 14 of 14 Posts
Top