Has anyone had a discrepancy between the TPS and a manual air pressure? My TPS reads about 2-3 PSI less than taking a measurement off of the valve. This is consistent (have used multiple gauges).

Which should i use?

Mark

 

The TPMS has been known to not be 100% accurate. Mine seem to be consistently above about 1 psi. Definately use your gauges. I think the TPMS is there more to warn you if your dealing with a serious loss of pressure than to actually read out accurate psi numbers.

 

Always use your good old guage. The TPMS is not fully accurate.

 

I have never had a digital tire pressure gauge - always used the manual gauge. Just wondered if anyone had experience with the digital? It seems to me the digital would be more apt to loose its accuracy than the manual. Also, you would have one more item to worry about having batteries for.

 

I've had the same difficulty with accurate readings from the TPMS. Since getting my RL in August, my trusted digital gauge always reports 2 psi higher than the TPMS. I suppose the TPMS is doing its job. However, just keep the discrepancy in the back of your mind at all times.

 

yep it isnt really accurate and seems to be there more for a person to see if there are any issues than to use it as the way to determine actual air pressure.

i personally would rather not have the system there but whatever, what's there is there.

 

This morning our TPS began to chime that the tire pressures were below optimum. Inflated the tires to 34psi (hand gauge) and the message reappeared. I'll reset the messages once I return home and see if this gets rid of it.

 

Allow me to once again share an experience I had after getting my Pirelli's put on my OEM 18's. Driving home on a freeway from the Acura dealership the warning light appeared indicating that there was an issue with the tire pressure. I changed the MID readout to the TPMS screen and saw that 3 of my tires were below ideal pressure and thanks to the TPMS display, I was able to watch the rate of pressure decrease as I decided what to do. The pressure drop seemed slow enough that I decided to try to make it home - the thought of sitting on the side of the freeway with 3 flat tires and no phone (I was going to pick up my new bluetooth compatible phone later that day) was not really appealing to me. Luckily, I made it home with roughly 10psi in one of the tires and 14 in two others (approximate values because up here in Canada, our TPMS values are in kPa (kilopascals)). I pumped up the tires with my air compressor and called the dealer who quickly sent out a flatbed for the return trip to the dealership. As it turns out, some rookie technician had damaged/loosened the TPMS sensors when he put the Pirellis on which had caused the leaks. His supervisor had done one of the tires which explains why only 3 tires had leaks. The moral of this story is two fold:
1. Acura has a long way to go to train their technicians properly.
2. The TPMS sensors/display are a very valuable safety feature.

 

update - the wife just called and said that the error message had finally cleared on its own.

 

Excellent news.

 

Just a note to add to the confusion. Pressure sensors that we buy at Pep Boys for a few $$ are not precision instruments. They only give a vague indication of what the pressure really is. Case in point is my AC powered pump. It has a useless piece of crud gauge on it that is no less than 10 Psi low.

Anyway, if you want to read your tire pressure accurately it'll probably cost you a good penny to get a good gauge. In the meantime tirepressures are not constant when you drive (temperature affects it, of course) so all we really need is an indication. Also, when we use the same gauge on all our tires you can make sure they are inflated similarly even if they are a few Psi higher or lower than you think.

If the TPMS read within 3 Psi of my $15 gauge I'd be very impressed