Lavrishevo

iTrader: (1)

To each their own... These recommendations on the vehicle are specific to the type of tire the car came with. As mentioned, I’m not running stock tire size. Some vehicles spec different pressure in the front vs the back. I like to keep the front a bit more than the back. My personal preference. I deflate my AT tires down to 18 when I’m in soft sand and about 27 when I’m mudding. Then back to 36 on the street. The manual also says there is no need to change the transmission fluid. Think this is engineering as well?

Wilson2000

Absolutely "to each their own." However, you are dispensing bad information to others, saying it is not an engineering thing, but a comfort thing. Words matter. You have a responsibility to your readers to not mislead them especially when it comes to the safety of their vehicles.

If someone loses control of their vehicle due to loss of traction on a dry highway at posted speeds, and kills themselves or others, investigators will check the tire pressures. If they are to spec, according to the door sticker, nobody would be liable except the driver. If the tire inflation was far from spec, the person who inflated the tires could be liable. I'm not saying it is an open and shut case, I'm just saying it would be a consideration in the case, and for good reason.

It's not common, but huge liability cases have been decided based on tire inflation. There was a famous case where Ford and Firestone were off the hook because the rear tires on an Explorer were underinflated. Underinflated rear tires can cause a loss of control. In this case, a whole family died in the roll-over.

Lavrishevo

iTrader: (1)

Dude, what in the world are you talking about? It’s 3 lbs difference! 3 lbs more not less. You can run 45 lbs of pressure and it’s not going to make the car unsafe. It will ride like crap but the vehicle is perfectly fine. Totally ridiculous conversation. The pressure ratings on the tire supersede the sticker on the door. And nowhere did I talk about under-inflating tires on the SC. AT tires are when off roading going 15 mph. And you clearly failed to see that I said 36 on the street in my post. Or did you purposely leave this out to mislead? You think I’m off roading in the SC!? As I mentioned for the fifth time I’m not running stock tires or stock size so the information on the door is not exactly applicable to my application. I hope you can understand this. The ratings for the tire that you use is what you should follow. It’s also called recommended tire pressure...

GmanSC

I would not inflate over 44psi. The reason is when the tires get hot, the air expand. The warning is not there for fun.

Caflashbob

My tires at 33 cold run 36 hot on both my ls and Sc, have stem mounted Tpms on both.

Lavrishevo

iTrader: (1)

Absolutely, max pressure hot you don’t want to exceed I’m just making a point that this minimal difference in pressure discussion is not essential to the engineering of the vehicle. Technically your have less rolling resistance with higher pressure but the ride quality suffers a lot and more abuse is transferred into the suspension by over-inflating unnecessarily. Particularly with run flats. Now when it comes to larger tires and you are towing with a lot of weight on the rear end for example you do want to go to like 40 - 45 or so lbs. Again, applications vary depending on the vehicle, tire size, and what you are doing with it. No single solution for everything even within the same vehicle. Off roading in the GX460 it can be as low as 16 in the soft sand or as high as 45 towing.



Difficult to see but my tires have about 18 pounds of pressure in this picture

Wilson2000

When I addressed your post, my point wasn't to comment on anything you are doing with your vehicles or the tire pressures you are running. What I found objectionable, is you claiming the door sticker is a merely a recommendation for the best comfort. It's dangerous to mislead people this way. The door sticker specification is there to educate people so they don't inadvertently run the wrong pressures in the front or back as it can have a disastrous affect on handling and safety.

My point was not to irritate. Too, I don't want to discredit you, only what you are putting in writing. I simply want readers to become educated about proper inflation if they aren't already.

Caflashbob

FMany posts here about running different pressures. None with less than the door panel. May try the 36 on the front of my Sc. Car turns medium hard at 35/36 warmed up.

obviously car not made to rail corners. Chassis components flex I think also.

45 series did take a bit away. But the ride improvement was worth it.

Everything is a trade off.

costco put Tpms sensors in the car today so no tpms on the stems yet as i dismounted them in advance. Bet they put in 32 not 33 cold. Feels slightly soft. Let’s see if I am really that good at telling.

just a game to hone my skills.

Caflashbob

My passenger sides were 32psi. Drivers side 33. Seems I was a little right. I use nitrogen also.

may try 36 cold in the front next. Thanks for the suggestion

Wilson2000

It is best to not pay attention to anything but cold pressures, as that's what the door sticker and the max pressure on the sidewall refer to.

I don't see much of an advantage to running a higher pressure than the door sticker. Comfort aside, you want the greater contact patch the stock pressure provides. Besides being safer, it will make your tread wear more evenly. Generally, I monitor my tread wear evenness and adjust by a few pounds to correct for any uneven wear. Generally, people tend to run underinflated as air leaks out over time. This leads to more wear on the outside and inside edges of the tire. Overinflating a few pounds can provide some correction resulting in greater wear toward the center.

I only need to inflate my tires about every six months when I change the oil, or I'll check them anytime I'm taking a trip. I find they leak out 4-5 psi over six months, so I always inflate them a few pounds over spec. That way, as they leak down over time, I stay closer to the target pressure.

Caflashbob

if you are sensitive to your cars handling as I am installing an inexpensive TPMS on the oem Metal valve stems that shows the exact pressure on each tire is very helpful. The particular unit I selected readout is a small round one that fits into the cars cigarette lighter and its small size allows the ashtrays door to be able to be closed completely. The unit has adjustable pressure alarms and a temporarily accessible tire temp readout on the small screen.

here is a link to the unit I am using. This is eBay. Same unit is on Amazon for much less.

https://www.ebay.com/itm/Vesafe-Tire...-/174380578822

Enjoymycar

I also have the Vesafe air pressure valves on my SC. I love them and they are a lot less expensive than the TPM's in the tire.

Caflashbob

i looked at the web info on how to disable the oem TPMS and when I took my dash area apart my 08 did not match the available info. Later models seem to be different and versus look at the yellow light on the dash forever I paid to have the sensors changed out.

I have three vesafes now and ordered a fourth unit today

mandyfig

If you can be diligent and always watch your tire pressures, you can elect to disable the TPMS altogether and not deal with TPMS lights. YMMV.

Wilson2000

The TPMS lights haven't been a problem for me with my two Lexus vehicles including my 2008 SC. However, I understand the pre-2006 TPMS systems are more prone to trouble and more expensive to fix when need be.

When you say you can disable your TPMS as long as you are diligent about watching your tire pressures, do you mean monitoring them with the Vesafe product? Monitoring them manually is far from ideal as a leak can occur at any time and you may not know it until it becomes an emergency. A warning light is even better than the Vesafe, as one might not be watching the cig-lighter display. It's hard to miss the dash light in your face!