TCH tire pressure
#31
06-26-2006, 08:55 PM
Re: TCH tire pressure
A quick note about tire guages: ya get what ya pay for. Cheap guages don't seem to read with any degree of accuracy. My dad was going through guages like a chain smoker zips through cigarettes and I was really surprised at the variability of them.
I believe the VDIM relies heavily on consistant tire rotation among all four positions, so if you had significant pressure differences between the front and rear tires, I bet the VDIM would go crazy. Remember when Hal wouldn't open the pod bay doors for David?
I believe the VDIM relies heavily on consistant tire rotation among all four positions, so if you had significant pressure differences between the front and rear tires, I bet the VDIM would go crazy. Remember when Hal wouldn't open the pod bay doors for David?
#32
07-03-2006, 06:54 AM
TCH tire pressure - Word of Caution!!
Just a word of caution for the tire pressure discussion. Before taking any of the suggestions here about raising the pressures greatly for better mileage, make sure which tire you have. TCHs come with either Michelins or Bridgestones.
The Bridgestones have a MAX pressure of 51 PSI.
The Michelins have a MAX pressure of 44 PSI.
Some suggestions in earlier posts to have very high pressures would be dangerous if you have the Michelin tires.
So check which tire you have before increasing pressure. If you have the Michelins, I wouldn't go higher than 40 to be safe.
The Bridgestones have a MAX pressure of 51 PSI.
The Michelins have a MAX pressure of 44 PSI.
Some suggestions in earlier posts to have very high pressures would be dangerous if you have the Michelin tires.
So check which tire you have before increasing pressure. If you have the Michelins, I wouldn't go higher than 40 to be safe.
#33
02-10-2007, 07:31 PM
Re: TCH tire pressure
I've increased mine to 42/40 PSI and don't notice any difference in ride or road noise. I have 320 miles so far and measured the Bridgestone tires tread depth. All four are 9/32 on the outer groove and 10/32 on the inner grooves. I'll keep track of the tire wear and report how it changes.
#34
07-30-2007, 11:09 AM
Re: TCH tire pressure
With the treads on excessive tire wear, I thought it was time for an update on how my Bridgestone tires are holding up.
I've passed 21,000 miles on my TCH, and it is over a year old now. I have been rotating tires ever 5K miles. Current wear shows 6+ on the outer groove and 7+ on the inner. (the tires were 9 and 10 when I measured them at 320 miles.) I'm guessing I'll get over 50K miles at this rate. I am quite amazed the tires only wore down 1/32 the past 9,000 miles.
I have run 42 psi front, 40psi rear since the tires were new. For about the last 5,000 miles I increased tire pressures to 48 psi front and 46 psi rear. Don't forget to check your spare! Mine was down to 50psi when I checked it last week.
I've passed 21,000 miles on my TCH, and it is over a year old now. I have been rotating tires ever 5K miles. Current wear shows 6+ on the outer groove and 7+ on the inner. (the tires were 9 and 10 when I measured them at 320 miles.) I'm guessing I'll get over 50K miles at this rate. I am quite amazed the tires only wore down 1/32 the past 9,000 miles.
I have run 42 psi front, 40psi rear since the tires were new. For about the last 5,000 miles I increased tire pressures to 48 psi front and 46 psi rear. Don't forget to check your spare! Mine was down to 50psi when I checked it last week.
#35
07-30-2007, 05:14 PM
Re: TCH tire pressure
Thought I'd drop a quick note for folks that have a new TCH direct from the dealer and haven't checked the tire pressure yet. [Editor's note: This started out as a quick note and wound up being a long senseless babble. Apologies to the reader.]
I bought my TCH about 2.5 weeks ago.
I have a digital tire pressure meter at home. The car has the stock P215/60R16 Michelin's on it.
When I first bought the car, I checked the pressure when I was parked outside the front of my house. The meter read 39.5 and 39.0 depending on the tire. I didn't adjust the pressure because they weren't definitely "cold".
I just had the chance to check them "cold" for the first time (two weeks later). Each tire was either 39.0 or 38.5. (Which basically means the dealer filled them to 39.)
I'm inclined to err on the side of going w/the manufacturer's recommended tire pressure.
Warning: I admit that zero scientific/logic evidence goes into the following approach--it is just gut reaction.
I read this thread, thought about it a bit, and lowered each tire to 36.0 pressure. As noted here, the manufacturer's is 32PSI (or 35PSI at sustained high-speed). I'm going to run with them at 36 for a week or two....and think about whether I want to drop it down to 35, 34, 33 or 32.
In general, I'd rather have the pressure be a bit too high rather than a bit too low, which is why I'm up at 36. Frankly, my guess is I'll wind up lowering them to 33 or 34 after my next tank or two. It just bugs me not to be within the manufacturer's recommended range.
I know it is "safe" to keep them a bit over-inflated, which is why I'm trying 36. We'll see if that lasts (the back of my brain is already bugging me about it as I'm typing this).
One last point/question: No one here has talked about how the tire pressure might affect the performance of the VDIM system. Presumably, the system can adjust some for varied tire pressure, but my assumption would be that it would perform better (or at least be designed to perform) at the manufacturer's recommended pressure.
Any thoughts on this last point? (Or on my illogical 36 PSI strategy?
)
I bought my TCH about 2.5 weeks ago.
I have a digital tire pressure meter at home. The car has the stock P215/60R16 Michelin's on it.
When I first bought the car, I checked the pressure when I was parked outside the front of my house. The meter read 39.5 and 39.0 depending on the tire. I didn't adjust the pressure because they weren't definitely "cold".
I just had the chance to check them "cold" for the first time (two weeks later). Each tire was either 39.0 or 38.5. (Which basically means the dealer filled them to 39.)
I'm inclined to err on the side of going w/the manufacturer's recommended tire pressure.
Warning: I admit that zero scientific/logic evidence goes into the following approach--it is just gut reaction.
I read this thread, thought about it a bit, and lowered each tire to 36.0 pressure. As noted here, the manufacturer's is 32PSI (or 35PSI at sustained high-speed). I'm going to run with them at 36 for a week or two....and think about whether I want to drop it down to 35, 34, 33 or 32.
In general, I'd rather have the pressure be a bit too high rather than a bit too low, which is why I'm up at 36. Frankly, my guess is I'll wind up lowering them to 33 or 34 after my next tank or two. It just bugs me not to be within the manufacturer's recommended range.
I know it is "safe" to keep them a bit over-inflated, which is why I'm trying 36. We'll see if that lasts (the back of my brain is already bugging me about it as I'm typing this).
One last point/question: No one here has talked about how the tire pressure might affect the performance of the VDIM system. Presumably, the system can adjust some for varied tire pressure, but my assumption would be that it would perform better (or at least be designed to perform) at the manufacturer's recommended pressure.
Any thoughts on this last point? (Or on my illogical 36 PSI strategy?
)Last edited by agnosto; 07-31-2007 at 04:30 PM.
#36
07-30-2007, 06:39 PM
Re: TCH tire pressure - Word of Caution!!
Just a word of caution for the tire pressure discussion. Before taking any of the suggestions here about raising the pressures greatly for better mileage, make sure which tire you have. TCHs come with either Michelins or Bridgestones.
The Bridgestones have a MAX pressure of 51 PSI.
The Michelins have a MAX pressure of 44 PSI.
Some suggestions in earlier posts to have very high pressures would be dangerous if you have the Michelin tires.
So check which tire you have before increasing pressure. If you have the Michelins, I wouldn't go higher than 40 to be safe.
The Bridgestones have a MAX pressure of 51 PSI.
The Michelins have a MAX pressure of 44 PSI.
Some suggestions in earlier posts to have very high pressures would be dangerous if you have the Michelin tires.
So check which tire you have before increasing pressure. If you have the Michelins, I wouldn't go higher than 40 to be safe.
Anyone old enough to remember Tom McCahill taking the auto manufacturers to task for recommending low tire pressures for their cars?
Once he set up a demonstration whereby he rolled all four tires off their rims in high speed turning maneuvers at the recommended tire pressure.
I have always gone straight to the tire to see what the recommended pressure should be set at and I keep my Michelin's, with a max recommended pressure of 44 psi, set at 42/40.
#37
07-30-2007, 06:48 PM
Re: TCH tire pressure
IMPORTANT TIP: Each time you change your tire pressure settings, you must reset your TIRE PRESSURE WARNING RESET SWITCH. This should be done, for example, if you change from running 32 PSI to 34 PSI, or from 38 PSI to 37 PSI, etc. Your sensor must accurately recognize your starting pressures to properly detect if a change in your tire pressures might occur. So, for all of you who are experimenting with tire pressures, don't forget to do a reset EACH time. The simple instructions are on Page 174 of the Owner's Manual. Basically, you Power ON, then press the Reset switch in the glovebox for a few seconds until your tire pressure icon on the main gauge display slowly flashes three times.
See, a friend of mine believes these tire pressure monitoring systems are detecting the speed at which each tire spins and are looking for different values. If that is the case, it wouldn't matter what pressure all 4 tires were at, if they were all within a certain range, the indicator would never come on.
#38
07-30-2007, 07:08 PM
Re: TCH tire pressure
Ah, starting to do some research to answer my own question.
http://en.wikipedia.org/wiki/Tire_Pr...itoring_System
So, my friend was talking about and Indirect TPMS system.
Now, what does Toyota use?
Well I didn't have to go far <g>, in another thread:
https://www.greenhybrid.com/discuss/...0&d=1156519812
(thanks schmidtj)
and here:
http://www.tirereview.com/?type=art&id=81377
Interesting, they are now required on all new cars: http://www.theautochannel.com/news/2...12/028379.html
http://en.wikipedia.org/wiki/Tire_Pr...itoring_System
So, my friend was talking about and Indirect TPMS system.
Now, what does Toyota use?
Well I didn't have to go far <g>, in another thread:
https://www.greenhybrid.com/discuss/...0&d=1156519812
(thanks schmidtj)
and here:
http://www.tirereview.com/?type=art&id=81377
Interesting, they are now required on all new cars: http://www.theautochannel.com/news/2...12/028379.html
#39
07-30-2007, 07:43 PM
Re: TCH tire pressure - Word of Caution!!
I found very good explanation here:
http://www.tirerack.com/tires-techpage-1/21.shtml
#40
07-31-2007, 07:35 AM
Re: TCH tire pressure
Your best bet is to stay with oem recommended tire pressure. You will notice little if any improvement on FE by going to max (tire wall max) psi. You will however notice handling difference. In my case, the handling improved all around, especially in the rain.
