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Post by betonthis1 on Oct 22, 2005 14:24:55 GMT -6
I just checked my tire pressure for the first time since i had them and i noticed two of my valve caps was missing. but i checked my tires and they were about 35 to 40 psi which is low for 51 PSI. what is your max tire pressure and how often are you checking yours?
also man that sucks if someone stole my valve stem covers. there chrome so im going to have to get 4 matching ones.
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Post by Aurora40 on Oct 22, 2005 16:25:00 GMT -6
You put your tire pressures at 51psi? What's the max pressure rating stamped on the sidewall? Most tires have a max pressure rating of 35-45psi.
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Post by betonthis1 on Oct 22, 2005 16:39:13 GMT -6
You put your tire pressures at 51psi? What's the max pressure rating stamped on the sidewall? Most tires have a max pressure rating of 35-45psi. yeah Max is 51 PSI. my Explorer is 50 but most cars I have owned it was 35.
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Post by 95mushroom on Oct 22, 2005 17:03:22 GMT -6
also man that sucks if someone stole my valve stem covers. there chrome so im going to have to get 4 matching ones. Yea, that happens all the time. Everyone loves to take chrome valve stem covers. I think they have locking ones on ebay with the Olds logo, or harder to take ones. No sure. Were they 2 on the same side?
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Post by TheLoveThatNeverDies on Oct 22, 2005 17:33:23 GMT -6
Low profile tires take more pressure than regular tires. On my Accord, I ran 20" 35-series and always kept them at 50 psi. However, it wasn't unusual for me to check the pressures and find one that was 10-15 psi low every now and then.
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Post by Aurora40 on Oct 22, 2005 17:39:39 GMT -6
I have 35-series factory tires. The recommended inflation pressure is 30 psi.
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Post by 97abrora on Oct 22, 2005 18:55:54 GMT -6
Mine says Max is 42PSI for 18" tires...
I believe they are filled at 40.. or they were.
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Post by TheLoveThatNeverDies on Oct 22, 2005 19:10:20 GMT -6
I believe the ones that I mentioned were Falken Azenis 115s. 50 was the max psi (cold), so that's where I kept them.
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Post by betonthis1 on Oct 22, 2005 23:08:40 GMT -6
also man that sucks if someone stole my valve stem covers. there chrome so im going to have to get 4 matching ones. Yea, that happens all the time. Everyone loves to take chrome valve stem covers. I think they have locking ones on ebay with the Olds logo, or harder to take ones. No sure. Were they 2 on the same side? yeah both were on the pass side.
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Post by Aurora40 on Oct 23, 2005 7:13:13 GMT -6
Just FYI, but the max pressure is not the recommended pressure. The stock tires on my Aurora have a max pressure of 45psi, but that would be way overinflated for normal driving. You might try contacting the company that makes your tire for a pressure suggestion (tell them the weight on each tire), or try marking the sidewalls and playing with pressures. Just cranking them up to the max listed pressure doesn't seem like the way to go.
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Post by betonthis1 on Oct 23, 2005 12:16:07 GMT -6
Just FYI, but the max pressure is not the recommended pressure. The stock tires on my Aurora have a max pressure of 45psi, but that would be way overinflated for normal driving. You might try contacting the company that makes your tire for a pressure suggestion (tell them the weight on each tire), or try marking the sidewalls and playing with pressures. Just cranking them up to the max listed pressure doesn't seem like the way to go. well thats the only pressure measurement on the whole tire. and working at a gas station/repair shop for two years one of my duties besides the cashier was to check oil and tire pressure of customers vehicles. the mechanics told me to fill up to the max tire pressure when doing so. how do you know where to fill it up to if there is no other tire pressure amount on the tire besides Max.? also i just emailed the manufacturer of my tire to get their recommendation.
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scottydl
Super Moderator
There's nothin' like an American V-8...
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Post by scottydl on Oct 23, 2005 14:08:19 GMT -6
also i just emailed the manufacturer of my tire to get their recommendation. This is your best bet... as you mentioned, there is no way to know otherwise. I would think that the normal ride PSI should be lower than the max, since that's how it is with most stock tires. If you look at the PSI indicated on the doorframe, I'm sure it's less than the max PSI for whatever brand tire you have. You'll reduce your traction and the life of your tire (because it will wear unevenly) if you inflate them more than necessary.
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Post by betonthis1 on Oct 23, 2005 17:40:35 GMT -6
also i just emailed the manufacturer of my tire to get their recommendation. This is your best bet... as you mentioned, there is no way to know otherwise. I would think that the normal ride PSI should be lower than the max, since that's how it is with most stock tires. If you look at the PSI indicated on the doorframe, I'm sure it's less than the max PSI for whatever brand tire you have. You'll reduce your traction and the life of your tire (because it will wear unevenly) if you inflate them more than necessary. funny cause i heard the opposite. under inflated tires well worsen gas mileage and cause uneven wear on the tires. but what your saying about the term "recommended" as opposed to "maximum" makes sense. i will see what they say. hopefully some more 20" owners can confirm since most of us have the same size tire.
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Post by Aurora40 on Oct 23, 2005 17:41:21 GMT -6
I would say the manufacturer is the way to go for sure, at least for the initial setting. You can then play around with slightly higher and slightly lower pressures to see how it feels. Make sure you are giving them the weight of the car. You can figure this out from the curb weight and weight distribution. So it's roughly 1,185 lbs on each front tire, and 695 lbs on each rear one. This is with no people or junk in the car.
You can also mark the sidewall with chalk, and see how far over the sidewall rolls. Let more air out or put more in until it's good. Letitroll can probably tell you more specifically what to look for and where you want the chalk to wear away from.
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Post by betonthis1 on Oct 23, 2005 18:21:37 GMT -6
how did you determine the weight for each tire? is the weight different in the front because of the engine? interesting.
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scottydl
Super Moderator
There's nothin' like an American V-8...
Posts: 7,373
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Post by scottydl on Oct 23, 2005 19:17:02 GMT -6
You'll reduce your traction and the life of your tire (because it will wear unevenly) if you inflate them more than necessary. funny cause i heard the opposite. under inflated tires well worsen gas mileage and cause uneven wear on the tires. Well it goes both ways... too much air OR too little air will skew the intended shape/wear pattern of the tire.
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20inchaurora
Aurora Passenger
"not your father's oldsmobile"
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Post by 20inchaurora on Oct 23, 2005 22:09:33 GMT -6
what make are your tires betonthis? im only runnin 35 in my toyos, and the max is 40....
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Post by betonthis1 on Oct 24, 2005 0:51:52 GMT -6
my brand is Nankang. i just got two emails from them. lol, they asked for more info on my vehicle but he told me that the tire pressure should be 55psi if not at least 51psi. wow.
as you can tell from his grammar that he is in some foreign country.
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Post by Aurora40 on Oct 24, 2005 6:18:21 GMT -6
how did you determine the weight for each tire? is the weight different in the front because of the engine? interesting. 3,962 lbs curb weight, 63/37 front to rear split. In regards to that letter, the rating on the sidewall is not recommended, that's the max pressure the tire can safely handle. Meaning, you should never exceed that pressure. Saying that it is recommended is like saying the date on a bottle of milk is the day you should start drinking it.
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scottydl
Super Moderator
There's nothin' like an American V-8...
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Post by scottydl on Oct 24, 2005 8:45:59 GMT -6
Saying that it is recommended is like saying the date on a bottle of milk is the day you should start drinking it. Hey, I've done that recently... ;D
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Post by betonthis1 on Oct 24, 2005 9:52:10 GMT -6
In regards to that letter, the rating on the sidewall is not recommended, that's the max pressure the tire can safely handle. Meaning, you should never exceed that pressure. So should I not do the 55psi like Nankang has stated in the email? Does that make sense to you about adding 10% more then the original pressure if I plus size my tires? I'm confused.
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Post by Aurora40 on Oct 24, 2005 10:23:24 GMT -6
Well, that email reads like the guy isn't very technical. First he says 10%, which would be 33psi. Then he suggests you use a pressure rating beyond the one at which the tire can safely operate.
If I were to take a guess, I would stick with somewhere in the 35-40psi range for now. Perhaps some other tire makers have more specific guidelines that could be used. What's the weight rating of the tires (hopefully 98 or greater!)? You can read it from the sidewall, it will say "245/35-R20" and then "98Z" or "102H" or something like that, where the number is the weight rating and the letter is the speed rating.
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Post by Mr. Javi on Oct 24, 2005 10:30:28 GMT -6
yup, just read the tire and go with that.
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Post by Aurora40 on Oct 24, 2005 10:45:10 GMT -6
Alright man, here's the scoop to the degree I can figure it out. Your tires have a load rating of 95, and that is an XL rating. This means they were rated at this load with a standard of 41psi in the tire. A non-XL tire would be rated at 35psi (meaning as a non-XL tire, this tire would probably have a load rating even lower than 95).
The load rating of 95 is below the OEM load rating of 98 that came on your car. It is rated at 1521 lbs per tire, vs OEM of 1653. A 130 lbs difference per tire (260 lbs on the front axle). So it's probably more important that you keep your fronts at the correct pressure, as they have less margin for error than the standard OEM tires.
So I'd say you absolutely should have 41psi or more in the tire at all times. I would think to have some margin for temp fluctuations you may want to go with 45psi or something, and then adjust it from there based on ride, handling, etc you experience.
I would suggest in the future that you ought to get a tire that has the same or better load rating than the OEM ones.
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Post by betonthis1 on Oct 24, 2005 10:52:18 GMT -6
Well, that email reads like the guy isn't very technical. First he says 10%, which would be 33psi. Then he suggests you use a pressure rating beyond the one at which the tire can safely operate. If I were to take a guess, I would stick with somewhere in the 35-40psi range for now. Perhaps some other tire makers have more specific guidelines that could be used. What's the weight rating of the tires (hopefully 98 or greater!)? You can read it from the sidewall, it will say "245/35-R20" and then "98Z" or "102H" or something like that, where the number is the weight rating and the letter is the speed rating. 95 (XL) is the load index. also my speed symbol is Y. whats the max speed for Y? oh nevermind i found out. 186mph. sweet!!! EDIT: Alright man, here's the scoop to the degree I can figure it out. Your tires have a load rating of 95, and that is an XL rating. This means they were rated at this load with a standard of 41psi in the tire. A non-XL tire would be rated at 35psi (meaning as a non-XL tire, this tire would probably have a load rating even lower than 95). The load rating of 95 is below the OEM load rating of 98 that came on your car. It is rated at 1521 lbs per tire, vs OEM of 1653. A 130 lbs difference per tire (260 lbs on the front axle). So it's probably more important that you keep your fronts at the correct pressure, as they have less margin for error than the standard OEM tires. So I'd say you absolutely should have 41psi or more in the tire at all times. I would think to have some margin for temp fluctuations you may want to go with 45psi or something, and then adjust it from there based on ride, handling, etc you experience. I would suggest in the future that you ought to get a tire that has the same or better load rating than the OEM ones. thanks for the info. so when i shop for tires i get 98 or higher for load index?
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Post by Aurora40 on Oct 24, 2005 11:56:57 GMT -6
Keep in mind tire pressures must be adjusted for higher speeds. You can't just punch it up to 186 (or 140) without considering that, especially with the lower weight rating of your tires. With a driver, you are at about 85% of the maximum load rating for the fronts.
And yeah, you'd want a rating of 98 or better, and not in a XL rating. 98XL would be a less capable tire than a 98.
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Post by betonthis1 on Nov 4, 2005 0:49:13 GMT -6
hey Aurora, you were dead on about the tire pressure. actually went to my Local Big 'O' and talked to the Manager there. i had dealt with him on some issues before with my Explorer and he broke it all down to me. My tire pressure should be the same as the OEM ones, doesnt matter what size i tire i get. he suggested keeping it around 30 to 35 psi and driving it around to see how it felt but if i put more weight on the vehicle then add more pressure. i brought my pressure down and ride is soo much smoother. thanks for your help dude.
also had a question for you about reading tire pressure. ok it lists on the door jam that the pressure should be 30 psi cold. if its warm from driving does it decrease or increase?
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Post by Aurora40 on Nov 4, 2005 8:07:59 GMT -6
It's a bad idea to fill them warm, it's hard to know if they are consistently warm across tires. But warm will raise the pressure. So 30psi cold is like 35psi hot. So don't set them to 30psi when they are hot. Also, if you have a garage, take that into account too. Add an extra 1psi for every 10 degrees difference (like add 2psi if your garage is 60F but outside is 40F).
However, since your tires are not the appropriate weight rating for your car, and are XL rated at that, I still would suggest 40-42psi, and then see how it drives/wears like that. Considering your tire pressure will only decrease, if you set it at 30psi and they drop to 27-28 before you check again, this will really affect their load capability. If you punch it up to 100 mph on a whim or something, this could be pretty risky.
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Post by eweath on Jan 9, 2006 22:00:22 GMT -6
uh duh its heavier in the front because of the engine!! sorry just so obvious
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Post by Letitroll98 on Jan 9, 2006 22:34:35 GMT -6
I'm sorry betonthis1, but you are not knowledgeable enough about tires to keep riding on the wheels you have presently mounted. You will be required to send them to me and I will replace them with a set of stock wheels and tires more suitable for your use, freight prepaid. Don't worry, I will be able to dispose of your wheels and tires without any state or federal authorities being informed of you use and they will be in the hands of someone who understands tire pressures, ratings, and loading factors.
Whew, good thing I got ahold of you before you drove any further miles on those wheels.
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