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Topic
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1. What is the correct tire pressure?
my car: 96 Suzuki Sidekick JX Sport 1.8L 4×4
I usually drive it on Rear-Wheel-DriveThe tire specification sticker on the edge of driver’s door is as follows:
GVWR
1670kg/3682lbGAWR FRT
800kg/1764lb
P215 65 R16
RIMS: 16×6 1/2J; 16×6 1/2JJ
160kPa/23psiGAWR RR
960kg/2116lb
P215 65 R16
RIMS: 16×6 1/2J; 16×6 1/2JJ
160kPa/23psi
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The sticker on the door shows 23psi, which I think is too low. In the Suzuki Forum, a moderator guy told me 23 psi was designed for stock tire that is a old-technology tire, NOT for today’s fuel-efficient tire (LLR tire).The ex-owner sold me this car with these mix-brand tires.
Driver Front: Dayton Quadra LTE, obvious dry-rod, 4/32 tread left. (Dayton is a brand. Quadra LTE is a series)
Driver Rear: Michelin MX4, severe dry-rod, 8/32 tread left.
Passenger Front: Dayton Quadra LTE, made on week 38 year 05, 6/32 tread left.
Passenger Rear: Firestone FR380, made on week 48 year 08, 8/32 tread left.
Spare: Dunlop SP4000T, 5/32 tread left.All tires are all-season tires in stock size – 215 65 R16, but NOT stock tire. (stock = original equipped)
Except for Spare tire(Dunlop one, 96T), all four tires have 98T index and are labeled max-load 750kg at max-pressure@44psiI has been suggested by walmart guy to replace at least two dry-rod tires, which are the Driver Front: Dayton and the Driver Rear: Michelin
I know mix-brand is NOT good. But, for this year, my budget only covers two new tires. Also, I am driving it in a town-size city. Most trips are within 15 miles.
Since last week, I have had two new tires (Walmart Goodyear Viva2, 215 65 R16, 98S) on the rear.
NOW,
Passenger Front: Firestone FR380, made at week 48 year 08, 8/32 tread left.
Driver Front: Dayton Quadra LTE, made on week 38 year 05, 6/32 tread left.When I inflate them to 30 psi, the sidewall close to the ground expands out like the left picture. But it is visible difference comparing to other part of sidewall. The steering is a little hard.
Two days ago, the temperature drops a lot, the tire pressure is 25.5 psi, the sidewall expanded out dramatically. It is known that under-inflation is much more dangerous than over-inflation (as long as not exceed max-pressure). I drive to the closest gas-station and inflated to 30 psi.
Yesterday, I inflated them to 35 psi. The steering is pleasant and smooth, but the drawback is tough ride-quality.
In this case, is 35 psi the best for my car and tires now?
2. Question about the direction of mounting tire.
The walmart guy, first mounted the wrong tire(the severe dry-rod Michelin with good tread) to a rim. When they done, I found that problem. Then, to correct it, he dis-mounted the severe dry-rod Michelin and mounted the ‘Dayton’ one with 6/32 tread to this rim after their closing hour(but they made mistake and they took the responsible).
However, yesterday, I found that the DOT label of the Driver Front ‘Dayton’ tire is inward (In other words, I cannot see DOT label on the outside sidewall), NOT outward like it supposed to be. Is it a BIG and safety issue?
The DOT label of other tires can be seen on the outside sidewall.
Are the tire patterns of my tires non-directional, symmetrical?
I attached a picture of my new Viva 2 tire. All my tires, including the ‘Dayton’ one, have the similar pattern – like diagonal grooves across from one side to the other.
Does it mean that the mounting direction could be either way (DOT label inward is not a big issue?) and crossing tire rotation is safe?
Thanks.
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Replies
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Some tires with softer sidewalls will tend to bulge more visually. I’d like to say that it is perfectly safe as long as it’s inflated to the placard specs. Personally I like to inflate to a few psi over spec, but that is personal preference. Tire pressure spec is determined mainly from the gross vehicle weight. Heavier vehicles generally call for more pressure and vise versa.
Directional tires must be mounted in the direction of rotation due to its tread pattern. Mounting them in the reverse direction of rotation will cause severe hydroplaning, undesired handling characteristics, and sometimes elevated tire noise. Directional tires cannot be rotated side to side without remounting and flipping the tire as you will find out.
Tires that are marked inner and outer must be mounted in that orientation. This kind of tire usually have specially engineered tread patterns and compounds so that the inner section of tread excels in straight line traction and the outer excels in cornering grip. You can rotate these tires to whichever corner you like as long as they are mounted to the wheel with the correct inner/outer.
[quote=”blacK20″ post=39864]Some tires with softer sidewalls will tend to bulge more visually. I’d like to say that it is perfectly safe as long as it’s inflated to the placard specs. Personally I like to inflate to a few psi over spec, but that is personal preference. Tire pressure spec is determined mainly from the gross vehicle weight. Heavier vehicles generally call for more pressure and vise versa.
Directional tires must be mounted in the direction of rotation due to its tread pattern. Mounting them in the reverse direction of rotation will cause severe hydroplaning, undesired handling characteristics, and sometimes elevated tire noise. Directional tires cannot be rotated side to side without remounting and flipping the tire as you will find out.
Tires that are marked inner and outer must be mounted in that orientation. This kind of tire usually have specially engineered tread patterns and compounds so that the inner section of tread excels in straight line traction and the outer excels in cornering grip. You can rotate these tires to whichever corner you like as long as they are mounted to the wheel with the correct inner/outer.[/quote]
My tires have neither marked inner and outer sign nor direction arrow on the sidewall. I think they are not asymmetrical, not directional; am I correct? Does it mean my tires could be mounted in either direction on the rim? Usually, people mount the side with DOT number with manufacture date outer. The guy of Walmart tire mounted my two new tires on the rim in this way, but didn’t mounted my old one in this way.
In terms of the tire pressure, the specs sticker shows 23 psi. However, 23 psi is correct for original equipped tires in 1996. The tire in 1996 is different from today’s tire. I think the majority of today’s tires around $100 is Low Rolling Resistance Tires (LLR tires). So, Viva 2 and my two old tires are most likely LLR tires. That is why I think 23 psi might NOT be correct for today’s tires.
I think you are over thinking this.
First of all, don’t go by what pressure the tire says as it is just letting you know the maximum safe pressure. The necessary tire pressure for your vehicle (light or loaded) is written in the owners manual or often on a sticker at the driver side door frame. 23PSI sounds low as most cars I know run ~28-34 PSI, but I don’t know you particular model and if it says 23 PSI make it in that ballpark. 35 PSI is too much and you tire looks overinflated.If for some reason you can’t find the correct pressure yourself or at a dealer, put in ~17 PSI, look at the tire and note how much bulging you have. Look at the picture you linked to. If it looks just a little under inflated, drive a short trip and see how it feels. Put in more air and try again. Under inflation will feel plush (comfortable some thinks), but will cause the car to roll/float on turns like off or on ramps. Too much air will make the tire contact on the middle and not at the sides. The car feels stiff and uncomfortable and people usually go under inflated and not overinflated for this reason.
If you cant judge how it feels, grap some fluor and dab it on the tire surface. Driver a few hundred yards and inspect where the flour is worn off. This will make it easy to tell if you are riding the shoulders (severely under inflated) or the middle of the tire (overinflated).
But as I said, don’t over think it as millions of cars drive around with wrong tire pressure all the time without accidents. Low pressure is bad for fuel economy and rainy weather and high pressure is primarily bad for comfort and suspension longevity. Most likely you will not experience anything else than slightly increased tirewear if you don’t get it exactly right.
I would still make sure it was right if it was me though 😉If you are unsure if they are fitted correctly, pictures of the tires on your car would help a lot.
P.s. The guy you bought the car from was a cheap bastard ;D. Using 4 different tires like that is unsafe and not recommended! As different tires distribute water differently and have different traction it can screw up your wet and winter driving, ABS and ECS. I know people on a budget do this or swap in pairs, I was on a budget too once. As a motorcycle driver I can tell you that tires and brakes should always be in pristine condition. The rest is just a bonus 🙂 (driving is a luxury you can live without, stopping isn’t).
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