Ideal tire pressure?
10-03-16, 08:34 PM
#46
noted- I am not going to go below 30, and will keep a close watch.....which is probably similar to shooting for 32-33 and finding that it drops with colder weather and ends up 2-3 psi below.....
Yes, new Toyota President Akio Toyoda wanted all Toyotas & Lexiis to have more inspired styling, and more inspired handling when he took over the reigns nearly ten years ago; this has come at a cost to both ride comfort and refinement.
Even if new president had not acted, there is a general trend to using low profile tires for esthetics anyway.
Just keep in mind that lowering the tire pressures causes increased deformation of the sidewalls as they roll, such that there is much greater internal heat build up at high speeds, leading to both greater tire wear, and high speed "blow-outs".
I normally use recommended tire pressures, because I only check my tire pressures monthly; four weeks later, the tires are below the recommended by 2-3 PSI anyway...
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Even if new president had not acted, there is a general trend to using low profile tires for esthetics anyway.
Just keep in mind that lowering the tire pressures causes increased deformation of the sidewalls as they roll, such that there is much greater internal heat build up at high speeds, leading to both greater tire wear, and high speed "blow-outs".
I normally use recommended tire pressures, because I only check my tire pressures monthly; four weeks later, the tires are below the recommended by 2-3 PSI anyway...
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10-03-16, 09:30 PM
#47
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There is no magic to the manufacturers recommended pressure. Tires are not automatically "unsafe" - few pounds be,ow or above.
10-04-16, 03:06 AM
#48
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Discount Tire recommended 31PSI on the new Pirelli's I just recently put on. I checked them with my own gauge, and they varied from 30PSI to 32. Those guys installing the tires don't get them exactly right.
You know I remember working in full service gas stations in the early 1970s, and we sold tires back then. The buzz back then was always 26 to 28PSI for radials, and 30PSI for 4-ply tires that weren't radials.
You know I remember working in full service gas stations in the early 1970s, and we sold tires back then. The buzz back then was always 26 to 28PSI for radials, and 30PSI for 4-ply tires that weren't radials.
10-04-16, 08:30 AM
#49
Discount Tire recommended 31PSI on the new Pirelli's I just recently put on. I checked them with my own gauge, and they varied from 30PSI to 32. Those guys installing the tires don't get them exactly right.
You know I remember working in full service gas stations in the early 1970s, and we sold tires back then. The buzz back then was always 26 to 28PSI for radials, and 30PSI for 4-ply tires that weren't radials.
You know I remember working in full service gas stations in the early 1970s, and we sold tires back then. The buzz back then was always 26 to 28PSI for radials, and 30PSI for 4-ply tires that weren't radials.
Yes, the modern day low profile tires require a little more pressure for support, otherwise the tread buckles gripping only at the inner and outer edges.
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Last edited by peteharvey; 10-04-16 at 03:41 PM.
10-04-16, 03:13 PM
#50
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Originally Posted by peteharvey
I presume you tested the cold pressures first thing in the morning.
Yes, the modern day low profile tires require a little more pressure for support, otherwise the tread buckles gripping only at the inner and outer edges.
Yes, the modern day low profile tires require a little more pressure for support, otherwise the tread buckles gripping only at the inner and outer edges.
If that were the case with the buckling I would have wear on the inner and outer edges of the tread, which I don't. Anyways the LS on question has 50 series tires so not really low profile. My GS on 45s was also fine.
10-04-16, 09:37 PM
#51
The whole thing is kind of nebulous. I wish I knew who within Lexus to contact to get the true story.
earlier in the thread I mentioned this :" What's interesting is that the recommended PSI on my 05 ES was 30, but the current ES recommends 33psi. Although I am pretty sure the older lexus may have been a heavier car...."
I had Michelin MXV4s on that car too. Granted, those were 16 inch and my new ES is 17 inch wheels. Never the less, I could have had 17 inch on that car too if I changed the wheels, and the placard does not say to change psi if wheel size is different. If that car was ok for Michelin MXV4s to be driven at 30 psi (or it might have been even 29 psi, I don't remember), then what is the reason why the same tire has to be 33 psi on the new ES, which is the same or lighter weight of a car?
earlier in the thread I mentioned this :" What's interesting is that the recommended PSI on my 05 ES was 30, but the current ES recommends 33psi. Although I am pretty sure the older lexus may have been a heavier car...."
I had Michelin MXV4s on that car too. Granted, those were 16 inch and my new ES is 17 inch wheels. Never the less, I could have had 17 inch on that car too if I changed the wheels, and the placard does not say to change psi if wheel size is different. If that car was ok for Michelin MXV4s to be driven at 30 psi (or it might have been even 29 psi, I don't remember), then what is the reason why the same tire has to be 33 psi on the new ES, which is the same or lighter weight of a car?
Yes lol, I know how to take tire pressures. Remember too my car tells me the pressures.
If that were the case with the buckling I would have wear on the inner and outer edges of the tread, which I don't. Anyways the LS on question has 50 series tires so not really low profile. My GS on 45s was also fine.
If that were the case with the buckling I would have wear on the inner and outer edges of the tread, which I don't. Anyways the LS on question has 50 series tires so not really low profile. My GS on 45s was also fine.
10-04-16, 09:41 PM
#52
none the less, if anyone reading this have their tires wear more quickly , or have a blow out due to lower pressures - yes, that is a risk with lower pressures....take heed
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For me, a risk worth taking for 2-3 psi lower and a softer ride.
...
For me, a risk worth taking for 2-3 psi lower and a softer ride.
The whole thing is kind of nebulous. I wish I knew who within Lexus to contact to get the true story.
earlier in the thread I mentioned this :" What's interesting is that the recommended PSI on my 05 ES was 30, but the current ES recommends 33psi. Although I am pretty sure the older lexus may have been a heavier car...."
I had Michelin MXV4s on that car too. Granted, those were 16 inch and my new ES is 17 inch wheels. Never the less, I could have had 17 inch on that car too if I changed the wheels, and the placard does not say to change psi if wheel size is different. If that car was ok for Michelin MXV4s to be driven at 30 psi (or it might have been even 29 psi, I don't remember), then what is the reason why the same tire has to be 33 psi on the new ES, which is the same or lighter weight of a car?
earlier in the thread I mentioned this :" What's interesting is that the recommended PSI on my 05 ES was 30, but the current ES recommends 33psi. Although I am pretty sure the older lexus may have been a heavier car...."
I had Michelin MXV4s on that car too. Granted, those were 16 inch and my new ES is 17 inch wheels. Never the less, I could have had 17 inch on that car too if I changed the wheels, and the placard does not say to change psi if wheel size is different. If that car was ok for Michelin MXV4s to be driven at 30 psi (or it might have been even 29 psi, I don't remember), then what is the reason why the same tire has to be 33 psi on the new ES, which is the same or lighter weight of a car?
10-05-16, 02:26 PM
#53
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I'll have to check them first thing in the morning when they are cold. I think I still remember the explanation my manger gave me on tire sizes when I was a 16-year-old working at a Sunoco gas station around 1974 or so. He said, take for instance a G78-15 tire. The G defines the distance between the rim and the outside of the tire. The 78 means that this distance is 78% of the width of the tire. The 15 is the rim size. So, a G70-15 would be a wider tire than a G78-15, but otherwise they are the same. What were those tires that everybody was putting on their Pontiac Trans Am's and Pontiac Firebirds back then?
10-05-16, 02:44 PM
#54
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I'll have to check them first thing in the morning when they are cold. I think I still remember the explanation my manger gave me on tire sizes when I was a 16-year-old working at a Sunoco gas station around 1974 or so. He said, take for instance a G78-15 tire. The G defines the distance between the rim and the outside of the tire. The 78 means that this distance is 78% of the width of the tire. The 15 is the rim size. So, a G70-15 would be a wider tire than a G78-15, but otherwise they are the same. What were those tires that everybody was putting on their Pontiac Trans Am's and Pontiac Firebirds back then?
10-05-16, 09:46 PM
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I think it was "BF Goodrich Radial T/A". I apologize for getting off topic.
https://www.google.com/search?q=1975...G1oxVp8X7CM%3A
https://www.google.com/search?q=1975...G1oxVp8X7CM%3A
10-10-16, 12:03 PM
#56
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I'll have to check them first thing in the morning when they are cold. I think I still remember the explanation my manger gave me on tire sizes when I was a 16-year-old working at a Sunoco gas station around 1974 or so. He said, take for instance a G78-15 tire. The G defines the distance between the rim and the outside of the tire. The 78 means that this distance is 78% of the width of the tire. The 15 is the rim size. So, a G70-15 would be a wider tire than a G78-15, but otherwise they are the same. What were those tires that everybody was putting on their Pontiac Trans Am's and Pontiac Firebirds back then?
As for my personal, non-professional opinion on the tire pressures blow out risk. The tires on our cars likely won't blow out unless driven under 20 psi for some number of miles. I attached a picture of the sidewall wear to look out for as a clue. Should see a mark or groove (worse) forming on the sidewall, where rim directly contacts the sidewall of a low pressure/flat tire. I saw it a lot when customers came in for flat repairs with an underinflated tire (10psi or lower). The groove will be some number of millimeters in depth too, before getting to the inner seal. If a mark is there, probably okay, repair flat or add air. If groove there, recommend replace tire.
As for the low/high pressure wear pattern on the tires. I have not appreciated this on a front wheel drive car. Therefore, I have not subscribed to it for front wheel drive cars. I have not seen it on my own car tires. I used to keep my front tires for civic at 32ish and rear at 35ish and 40 psi (all 4) for my corolla. Always too lazy to rotate, so 15k or so miles goes by. Each time, shoulder tread wore faster on the front tires from daily driving. Rear tires with even wear. Never saw center wear outpace the shoulder wear.
In the name of practicality, I inflate (cold) to 36 psi. When they eventually drift down to 28 psi or so, I re-inflate to 36 psi. As confessed above, I am also lazy. Anyway, I would not let my tires go below 25 psi, nor recommend it.
Richard
10-10-16, 06:53 PM
#57
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Endzone. Fellow former tire guy here (from 2000 - 2002). The old tire size you mention above. Was that for radials and ply? I don't remember seeing that on any standard car tires when I worked. Maybe just overlooked it?
As for my personal, non-professional opinion on the tire pressures blow out risk. The tires on our cars likely won't blow out unless driven under 20 psi for some number of miles. I attached a picture of the sidewall wear to look out for as a clue. Should see a mark or groove (worse) forming on the sidewall, where rim directly contacts the sidewall of a low pressure/flat tire. I saw it a lot when customers came in for flat repairs with an underinflated tire (10psi or lower). The groove will be some number of millimeters in depth too, before getting to the inner seal. If a mark is there, probably okay, repair flat or add air. If groove there, recommend replace tire.
As for the low/high pressure wear pattern on the tires. I have not appreciated this on a front wheel drive car. Therefore, I have not subscribed to it for front wheel drive cars. I have not seen it on my own car tires. I used to keep my front tires for civic at 32ish and rear at 35ish and 40 psi (all 4) for my corolla. Always too lazy to rotate, so 15k or so miles goes by. Each time, shoulder tread wore faster on the front tires from daily driving. Rear tires with even wear. Never saw center wear outpace the shoulder wear.
In the name of practicality, I inflate (cold) to 36 psi. When they eventually drift down to 28 psi or so, I re-inflate to 36 psi. As confessed above, I am also lazy. Anyway, I would not let my tires go below 25 psi, nor recommend it.
Richard
As for my personal, non-professional opinion on the tire pressures blow out risk. The tires on our cars likely won't blow out unless driven under 20 psi for some number of miles. I attached a picture of the sidewall wear to look out for as a clue. Should see a mark or groove (worse) forming on the sidewall, where rim directly contacts the sidewall of a low pressure/flat tire. I saw it a lot when customers came in for flat repairs with an underinflated tire (10psi or lower). The groove will be some number of millimeters in depth too, before getting to the inner seal. If a mark is there, probably okay, repair flat or add air. If groove there, recommend replace tire.
As for the low/high pressure wear pattern on the tires. I have not appreciated this on a front wheel drive car. Therefore, I have not subscribed to it for front wheel drive cars. I have not seen it on my own car tires. I used to keep my front tires for civic at 32ish and rear at 35ish and 40 psi (all 4) for my corolla. Always too lazy to rotate, so 15k or so miles goes by. Each time, shoulder tread wore faster on the front tires from daily driving. Rear tires with even wear. Never saw center wear outpace the shoulder wear.
In the name of practicality, I inflate (cold) to 36 psi. When they eventually drift down to 28 psi or so, I re-inflate to 36 psi. As confessed above, I am also lazy. Anyway, I would not let my tires go below 25 psi, nor recommend it.
Richard
I found out something interesting today. I had a new rim (salvage yard) put on my right front today. I bought the rim at a yard in south Dallas, and then went right over to the local Mexican tire shop to have the new rim and tire mounted and balanced and put on the right front. Man you talk about some old antique equipment. It even predates my tire busting years from 1974 to 1977. Anyway, unbeknown to me, the fellow there inflated the tire to 40psi. He did a good job on everything. The car has almost zero vibration in the floor or the wheel. I even gave him a $10 tip. But, I noticed the car was pulling to the left for some reason. When I got home I checked the pressure, and it was 40PSI! I lowered it to 31PSI like all my other tire are. After this I drove around, and the pulling to the left was almost completely gone. I didn't know an overinflated tire could cause a car to pull one way or the other.
10-11-16, 05:54 PM
#58
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I bet the guy probably needed 40 PSI to pop the bead on, forgot to deflate.. I've gone up to 60+ on low profile tires before. My buddies used to tell me occasionally using 80 PSI, then mounting the tires and driving around the parking lot before the beads would pop. Then deflating to appropriate pressure.
Just curious. How did they balance the tire? On the car? If so, consider me jealous.
Richard
10-11-16, 08:37 PM
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Interesting. Think lower rolling resistance on the over-inflated tire, lead to left side pull?
I bet the guy probably needed 40 PSI to pop the bead on, forgot to deflate.. I've gone up to 60+ on low profile tires before. My buddies used to tell me occasionally using 80 PSI, then mounting the tires and driving around the parking lot before the beads would pop. Then deflating to appropriate pressure.
Just curious. How did they balance the tire? On the car? If so, consider me jealous.
Richard
I bet the guy probably needed 40 PSI to pop the bead on, forgot to deflate.. I've gone up to 60+ on low profile tires before. My buddies used to tell me occasionally using 80 PSI, then mounting the tires and driving around the parking lot before the beads would pop. Then deflating to appropriate pressure.
Just curious. How did they balance the tire? On the car? If so, consider me jealous.
Richard
10-11-16, 08:41 PM
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I sure found out about the difference between cold morning air tire pressure and hot Texas afternoon sun tire pressure. I think there is about a 3lb difference. Whoever the poster was in this thread that pointed that out to me--thank you!