Any way I can set up the tire pressure warning to come on at 27psi or so? I want to set the tires at 30psi for a more comfy ride and not have the warning light on.
Don't care about mileage. Want the cushy Lexus ride.

 

At one time I read that the TPMS in Lexus / Toyota cars was designed to alert when tire pressure dropped by 6 psi. I didn't like that much of a spread so I over inflate my tires by three psi, reset the TPMS and then remove the extra 3 psi. So with my current ES which I want to run at 33 psi I inflate to 36 psi, reset the TPMS and then remove the extra 3 psi assuming that my TPMS will alert at 30 psi which is okay with me. My TPMS reports the pressure for each tire so this distinction is less important than it used to be but I still use it and it seems to work for me.

Dave Mac

 

I believe the TPMS reset procedure and button location (under the dash) is shown in the owners manual if you have one available. Otherwise a dealer can set if for you.

 

Friends suggesting to stay away from nitrogen.
What do you guys think?

 

Any improvement in fuel economy that results from nitrogen tire fills is minimal (if it exists at all) and likely to be temporary.

If you do have the tires filled with nitrogen, that means that, as the seasons change and as you add and remove air from the tires to compensate for changes in ambient temperature, you can't just add normal air because that will dilute the nitrogen already in the tires. So, when tire pressure needs to be increased, you need to go back to the dealer and spend time and, possibly, money to get the tire pressure back up to proper levels. Even adding a small amount of normal air to tires with nitrogen fills will completely eliminate any (minimal) gains that the nitrogen fills may otherwise give to fuel economy.

Many feel, and I am among them, that the nitrogen fills are largely only a way for dealers to pad their profits from selling and servicing vehicles.

 

Good if you are buying at Costco and it is free. (well, not free per se but included in the tire price)

Bad if you are buying at dealer/tires store and costs additional $$

 

I see no scientific basis for nitrogen. Air and nitrogen will both follow the 'perfect gas law' college 101 chemistry. There will be no difference.

 

One of the stated advantages of nitrogen is supposed to be less reaction to seasonal temperature changes - I currently have three cars in my garage most of the time two of which were delivered with nitrogen filled tires and if anything the nitrogen filled tires are more affected by temperature change. The difference is in the process of averaging out as I check and add air to cold tires as recommended using my own compressor. The two cars that came nitrogen filled came of course with green valve caps which I made the dealer replace so people wouldn't think I paid $100 for nitrogen which I did not.

I believe this has been discussed at great length here and I think again high school science taught that the air we breathe is 78% nitrogen anyway so even if the tires were vacuumed down which they are not you would only be getting 22% more nitrogen.

Dave Mac

 

The air you're breathing right now is 78% Nitrogen so ask your dealer if they'll give you a 78% discount on the Nitrogen tire fill. A waste of money IMO.

 

Yes, from some reading that I did on nitrogen fills some time ago, I understand that, with a properly done nitrogen tire fill, you are still only going to end up with about 92 or 93% nitrogen, and, since air already has 79% nitrogen, the additional nitrogen after the nitrogen fill is actually quite small.

 

At the dealership I work at the nitrogen air comes from the same air line as the regular air that we used on air tools it just magically changes when we inflate tires so do you really want to pay for something you're probably not getting?

 

That is consumer fraud but kind of what I expected at some dealers - it is just too tempting. I've never seen a tank of nitrogen at a dealers but some have a pretty simple little machine displayed prominently. AC repair guys use nitrogen for a lot of things like purging lines and if a person was really a believer in nitrogen filled tires I guess you could buy a small tank and regulator to top off the tires without driving 5 - 10 or 20 miles to a dealer. I don't think Discount uses or pushes tires and all the flat repairs they do get "regular" air.

I recently watched a Honda dealer swap tires on a new Accord with nitrogen and it appeared to me that he used the shop air hose and then put the green caps back on.

Dave Mac

 

True and honest words of wisdom...

 

I'm guessing the dealership also screws customers in other areas too?

 

Almost in every way