I understand that this may not appear to believable, but here is the truth.
Brought my 2006 DTS to the dealer for service of the Tire Pressure Monitor System. The tech replaced 3 out of 4 TPM sensors, so tires were dismounted, sensors replaced and remounted/rebalanced. My dealer uses Nitrogen not straight air to fill the tires. The tech did NOT follow the 30 Psi guidelines listed on the door pillar for my vehicle W/ 17" wheels.
Prior to this repair I have always maintained exactly 30 psi all tires measured cold, no less than 60 degrees F ambient with the readings taken in the shade.
The best MPG Cleveland to NY previous to this repair had been 22. 5 MPG. During my latest trip from Cleveland to NY I had an avg of 26.7 MPG., conservative driving, 65 - 70 MPH used cruise the entire way. The TPM warning was active for the right front tire and was reading between 39 and 40 (Hot) Psi on the DIC. The other tires were reading 36 - 37. There was a slight decrease in ride quality, you could feel the road texture right up to the steering wheel just a little more than usual.
At my destination in NY I checked the cold Tire Pressure, approx 70 degrees F ambient temperature and in the shade. The cold Psi for all tires ranged from 33-36 Psi. I left all the tires overinflated. They are well in the safe inflation range, IMO there is no increased risk of thread separation or blowout at these inflation levels. The vehicle weight to tire rating ratio maintains a factor of safety.
The 3- 4 MPG improvement is still being maintained several weeks later in a mix of City/Hwy driving (more hwy than city). In city driving, the decreased rolling resistance is definitely noticeable
I don't plan on pushing the envelope by operating at 40 PSI hot for future highway extended trips. I plan on maintaining the hot tire pressure operating at 37 psi or less. BTW I am running Falken Ziex 502 tires.
Although its logical to attribute the major factor for the increase in gas mileage to the higher inflation, I am wondering if the nitrogen has enough of a positive impact on tire balance at highway speeds to be a minor contributor to the increase.
Any thoughts or similar experiences?
Brought my 2006 DTS to the dealer for service of the Tire Pressure Monitor System. The tech replaced 3 out of 4 TPM sensors, so tires were dismounted, sensors replaced and remounted/rebalanced. My dealer uses Nitrogen not straight air to fill the tires. The tech did NOT follow the 30 Psi guidelines listed on the door pillar for my vehicle W/ 17" wheels.
Prior to this repair I have always maintained exactly 30 psi all tires measured cold, no less than 60 degrees F ambient with the readings taken in the shade.
The best MPG Cleveland to NY previous to this repair had been 22. 5 MPG. During my latest trip from Cleveland to NY I had an avg of 26.7 MPG., conservative driving, 65 - 70 MPH used cruise the entire way. The TPM warning was active for the right front tire and was reading between 39 and 40 (Hot) Psi on the DIC. The other tires were reading 36 - 37. There was a slight decrease in ride quality, you could feel the road texture right up to the steering wheel just a little more than usual.
At my destination in NY I checked the cold Tire Pressure, approx 70 degrees F ambient temperature and in the shade. The cold Psi for all tires ranged from 33-36 Psi. I left all the tires overinflated. They are well in the safe inflation range, IMO there is no increased risk of thread separation or blowout at these inflation levels. The vehicle weight to tire rating ratio maintains a factor of safety.
The 3- 4 MPG improvement is still being maintained several weeks later in a mix of City/Hwy driving (more hwy than city). In city driving, the decreased rolling resistance is definitely noticeable
I don't plan on pushing the envelope by operating at 40 PSI hot for future highway extended trips. I plan on maintaining the hot tire pressure operating at 37 psi or less. BTW I am running Falken Ziex 502 tires.
Although its logical to attribute the major factor for the increase in gas mileage to the higher inflation, I am wondering if the nitrogen has enough of a positive impact on tire balance at highway speeds to be a minor contributor to the increase.
Any thoughts or similar experiences?