Own my 2020 now 18 mos @ 12kmiles. Covid had me working at home. Long story to why, but was running the Tire pressure at 32-33. I ignored many times advice on these very pages to inflate to psi. I have done so and 10% better MPG right off the bat and over all better handling. As as a public service reminder this was good advice Im simply passing along.

I never had a car with a tire monitor that kept the Tire pressure numerically so I believe I lowered it feeling the car rode too hard and saw 40psi.
Thats been remedied.

 

The PSI will increase with driving or if one side sits in the sun, they can be a few PSI higher. As the weather cools, people need to air up their tires.

 

I have always maintained all my vehicles' tire pressure at an 'elevated' tire pressure compared to what is recommended by the carmaker. I can tell the immediate difference in as little as 2 psi. I have never liked a mushy soft tire with the recommended air pressure or less. Not only is fuel mileage improved with higher air pressure, but handling is also improved as well. And, from what I have experienced running 'elevated' tire pressure is that tires wear more evenly across the face of the tire instead of increased shoulder wear which is common when running recommend or lower air pressure. Running 'elevated' tire pressure definitely increases tire mileage.

Just a few days ago I dropped by my local Discount store which is 1.5 miles from my house to tweak my tire pressure. I always like to do this after my car has been in the dark garage overnight as both driving and the sun's radiation will increase tire pressure. The recommended tire pressure for my car is 33 psi. I had my relatively 'cold' tires inflated to 37 psi. Perfect!

The problem of maintaining tire pressure where you want it comes about when there is a difference in ambient temperature versus tire temperature, which requires a compensation adjustment. People living in cold areas that often deal with sub-freezing or sub-zero temperatures must compensate the most for the temperature differences between psi test temperature and drive temperature.

Below (in attachment) is Tire Pressure Inflation Compensation & Adjustment Information

 

Exactly same observation in my 2016 GS 200T. I keep my tire pressure at 32-33 psi cold which increases to 35-36 psi on the highway. The explanation behind higher mpg with low pressure might be that the wheels weigh more when tires have higher pressure.

My tires are 4yrs 9mos old with about 25k miles on them, rotated once every year. They still have usable tread life.

 

Are you sure 'bout that?

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higher mpg with low pressure

Tell me more about higher (better) fuel mileage running lower air pressure!

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the wheels weigh more when tires have higher pressure

Tell me more about how the wheels weigh more when tires are inflated to higher air pressure!

 

You beat me to it. The "weight" of air at 1PS vs 100PSI is not going to affect the wheel weight in any meaningful way. It would have to be liquid air to add weight.

 

I am not 100% sure about my explanation but I am 100% sure that my mpg drops noticeably in the same route if my tire pressure is higher.

 

Too many variables to make such a bold statement. Traffic, speed, weather and other weight in the car all impact it. Most definitely, more air pressure will reduce rolling resistance in a tire, not increase it. You will get the best gas mileage if you had 4 of the spares. They are skinny and inflated to 60PSI.

 

This has become a very weighty topic!

 

I have been driving the exact same route every weekday twice (going and coming) on the same set of tires since I bought my GS. I have experimented with high and low tire pressures for extended periods of time during the last ~5 years and then came to the conclusion. This I have observed in my other cars as well.

Skinny spares (rim+tire) often weigh less than the OEM wheels (rim+tire) when both are fully inflated to specs. So one should get higher mpg with such spares.

 

You missed the point!

Simply put, to overemphasize the point - if you increased the tire pressure of all four tires to let's say 200 psi, each tire/wheel combo would weight no more, or no less, than if the tires had 35 psi in them, or only 6 psi in them. And due to the reduced rolling resistance created by the tires being overly inflated the fuel mileage would be greater (higher), not less (lower) as you incorrectly proclaim. Of course you'd have a very dangerous and uncomfortable ride with 200 psi in the tires! The psi air measurement is pounds of expanding pressure per square inch of volume. Essentially, for all practical purposes air in a tire weighs nothing because it equals the atmosphere in which it is used.

When you fill a low bicycle tire that only has 5 psi in it to say 44 psi, the tire and wheel combo doesn't weigh more than it did when it only had 5 psi air pressure in the tire!

 

What about using Helium? If the tires started to make noise, it would sound funnier?

 

Anyone that has had to push something knows a flat tire rolls poorly.

 

Will you please clarify the psi you are running? I would like to try it.

 

I just upped my PSI a bit the other day, I'm now running 38 front and 39 rear from 35/36 cold. They go up to about 44 PSI when hot and stays there.

Maybe if I pump them to 60 PSI I would get 60 MPG?