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Tire pressure makes huge difference in smoothness?
Bought a 2023 CPO ES 350 about 14 months ago.
Living in PA, the cold temps kicked in in full force this past week. Got in my car Monday and the tire pressure light came on. I checked, using the dashboard info view, and it showed the two back tires at 29psi.
Using a portable Ryobi compressor (the version made specifically for tires - you insert one of the Ryobi 18v batteries that are used for all the other Ryobi tools into it) and inflated to the 35psi (cold) specified on the door sticker.
Result:
Car rides noticeably smoother and a little quieter. It was quiet before but it's definitely a bit more smooth and more "cushiony" if that word makes any sense?
We're only talking 6 psi difference (I checked and the front tires were at 30 or 31 so I filled them all to the specified 35).
However....the dashboard is showing them all between 30 and 32psi. I am not due for a scheduled maintenance until the Spring. Is this something I should ask them to look at to recalibrate? Or is it likely my Ryobi inflator tool? I am going to see if I can find the old school guage I used to have and check it.
Tire pressure gages will differ among other measuring pressure gages as well as from the vehicle TPMS signal numbers.
Probably your Ryobi tool not accurate.
Get a better gage to check pressures, those portable pressure tools are not that accurate based on ones I have used..
With gages used to measure it is best to use the same one for relative consistency.
Even the same brand gage and type will be different among others of the same brand and type, considering manufacturing tolerance allowed.
Then there are analog vs digital gage differences.
I prefer analog, old school here
The Ryobi tools show two pressures. When you are holding the trigger to inflate, the pressure that is showing is the input pressure from the inflator to the tire. It is always a few psi higher then the psi in the tire. When you release the trigger, the display then shows the actual tire PSI which should be a few lower.
Originally Posted by mark2741
Bought a 2023 CPO ES 350 about 14 months ago.
Living in PA, the cold temps kicked in in full force this past week. Got in my car Monday and the tire pressure light came on. I checked, using the dashboard info view, and it showed the two back tires at 29psi.
Using a portable Ryobi compressor (the version made specifically for tires - you insert one of the Ryobi 18v batteries that are used for all the other Ryobi tools into it) and inflated to the 35psi (cold) specified on the door sticker.
Result:
Car rides noticeably smoother and a little quieter. It was quiet before but it's definitely a bit more smooth and more "cushiony" if that word makes any sense?
We're only talking 6 psi difference (I checked and the front tires were at 30 or 31 so I filled them all to the specified 35).
However....the dashboard is showing them all between 30 and 32psi. I am not due for a scheduled maintenance until the Spring. Is this something I should ask them to look at to recalibrate? Or is it likely my Ryobi inflator tool? I am going to see if I can find the old school guage I used to have and check it.
Bought a 2023 CPO ES 350 about 14 months ago.
Living in PA, the cold temps kicked in in full force this past week. Got in my car Monday and the tire pressure light came on. I checked, using the dashboard info view, and it showed the two back tires at 29psi.
Using a portable Ryobi compressor (the version made specifically for tires - you insert one of the Ryobi 18v batteries that are used for all the other Ryobi tools into it) and inflated to the 35psi (cold) specified on the door sticker.
Result:
Car rides noticeably smoother and a little quieter. It was quiet before but it's definitely a bit more smooth and more "cushiony" if that word makes any sense?
We're only talking 6 psi difference (I checked and the front tires were at 30 or 31 so I filled them all to the specified 35).
However....the dashboard is showing them all between 30 and 32psi. I am not due for a scheduled maintenance until the Spring. Is this something I should ask them to look at to recalibrate? Or is it likely my Ryobi inflator tool? I am going to see if I can find the old school guage I used to have and check it.
Could look at it this way - 6 psi is about 17% of the suggested inflation pressure That's quite a bit.
I wouldn't necessarily trust the Ryobi tool reading...you're always better off using a separate pressure gauge and creeping up (or down) to the correct PSI using a compressor/deflator. Its very possible you didnt get to a true 35 with the unit, and the TPM sensors are (mostly) correct
I just filled the tires on my truck yesterday and the first digital pressure gauge I used felt off...TPM said 32 psi but the gauge said 37... Changed to a different gauge and it matched the TPM. After all 4 were done, the measured pressure and TPM read pressure matched perfectly. I believe TPM sensors are fairly accurate as long as the batteries are still good (my truck sensors are 8 years old at this point)
I used to set my CT's tires to 42 psi. Helped me get 50 mpg and I always liked how it felt - peppy and smooth. However I stopped when I realized techs were setting it back to 36 any time I serviced the car, and I got tired of going back and forth.
I've gone crazy trying to get consensus between gauges. I have two Jaco FloPro digital gauges that are suppose to have a specified accuracy of +/-1% Full scale meaning they should have been accurate to within +/- 2 psi since FS= 200 PSI. They often measure over 5 PSI apart and it's not always repeatable. So I tried comparing against pencil still gauges, ok now I have three majorly different readings. Maybe I need to try an old fashioned analog dial gauge but the digital ones actually had better user reviews.
Last edited by hotwings; Dec 11, 2025 at 09:19 AM.
Could look at it this way - 6 psi is about 17% of the suggested inflation pressure That's quite a bit.
I wouldn't necessarily trust the Ryobi tool reading...you're always better off using a separate pressure gauge and creeping up (or down) to the correct PSI using a compressor/deflator. Its very possible you didnt get to a true 35 with the unit, and the TPM sensors are (mostly) correct
I just filled the tires on my truck yesterday and the first digital pressure gauge I used felt off...TPM said 32 psi but the gauge said 37... Changed to a different gauge and it matched the TPM. After all 4 were done, the measured pressure and TPM read pressure matched perfectly. I believe TPM sensors are fairly accurate as long as the batteries are still good (my truck sensors are 8 years old at this point)
I bought a ASTROAI Tire Inflation compressor this summer and it matches the Lexus App and my dash exactly, immediately after filling them. Not that it's that important, as tire pressure will fluctuate with the weather and whether you've been driving or not. A few pounds is not going to make much difference. Here in Minneapolis this week, the temperatures will range from 33 degrees to 15 below zero. And the tire pressure will move around accordingly. As much as losing 4 pounds when it's below zero, and rising again when it warms up by 40 degrees.
I worked in a Tire Shop over 50 years ago in high school and mounted hundreds of sets of tires. We had the manual tire pressure gauges and they all worked and were similar.
Last edited by Cut-Throat; Dec 11, 2025 at 10:40 AM.
I used to set my CT's tires to 42 psi. Helped me get 50 mpg and I always liked how it felt - peppy and smooth. However I stopped when I realized techs were setting it back to 36 any time I serviced the car, and I got tired of going back and forth.
Another one of the benefits of living in the paradise state of California. California's benevolent overlords have dictated that all automotive maintenance or repair service providers must (per California Code of Regulations, subarticle 8, section 95550):
(d)...(1)...(A) check and inflate each vehicle’s tires to the recommended tire pressure rating, with air or nitrogen, as appropriate, at the time of performing any automotive maintenance or repair service; ...
Car rides noticeably smoother and a little quieter. It was quiet before but it's definitely a bit more smooth and more "cushiony" if that word makes any sense?
I'd have thought that lower pressure tires would give you a more cushiony ride. Having said that, I recommend keeping them at the recommended 35 psi.
I used to lower tire pressures for a smooth ride.
However, it does affect the fuel economy, handling and tire wear.
Ultimately, I had to change the coil springs, shock absorbers and the wheels sizes.
Why did you change coils springs and shock absorbers, was it when it had 19" tires hoping it would soften the ride?
How does it feel with the current setup using 17" tires in comparison?
Tire pressure makes huge difference in smoothness?
That's quite a bit.
