Tire Pressure

Rufio24 · 08-28-2007, 02:28 AM

I read somewhere on this site that the better the tire pressure, the better the mileage. My Goodyear Integrity tires say 44 psi, but my roommate said that might be too much. What is the optimal tire pressure for the Prius?

JimboK · 08-28-2007, 07:05 AM

44 is fine, though the consensus seems to be that fronts and rears should have a 2 PSI differential due to the car's front end weight. In other words, 44 front, 42 rear. 44 is the maximum cold sidewall pressure (meaning first thing in the morning before driving) specified by Goodyear. And what you've heard about pressure's relationship to fuel mileage is correct: The higher the pressure, the lower the rolling resistance.

AOV · 08-28-2007, 07:12 AM

I prefer 40/38, its less of a bumpy ride. Try out different tire pressures, its whatever you are comfortable with.

catgic · 08-28-2007, 08:09 AM

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patsparks · 08-28-2007, 08:17 AM

44 front 42 rear is good. As you said, the higher the better up to the tyres rated limit. Check tyres cold. Maybe inflate a few PSI over 44psi at a petrol station on your way home somewhere close to home then let the tyres down to the required pressure when the tyres are cold. You will need a good tyre gauge but they are cheap. Use dial type rather than stick type.

**TonyPSchaefer** · 08-28-2007, 09:32 AM

As they've already said above, the front should always be 2 psi higher.

People on PriusChat report tire pressures ranging from "factory installed" all the way up to "I don't want to scare you." At a Chicago Prius Group meeting, we sort of got a slap on the wrist for mentioning the idea of over-inflating tires for improved mileage. For that reason, we no longer promote the practice (publicly). But I can confirm, without self-incrimination, that 44 psi is just fine and within the tires' safety limit.

Your roommate is nice and considerate to be concerned about your car and your safety. Take them out to lunch and enjoy that you have such a friend.

JimN · 08-28-2007, 09:40 PM

I'm running 45psi. "Don't tell me what it is designed to do. Tell me what it can do." The spec on the door is a negotiation between Toyota & Goodyear. The spec on the tire is Goodyear's opinion. Optimizing your fuel economy is not in their best interest. The longer the tires last, the less they sell.

08-28-2007, 09:32 AM	#6
TonyPSchaefer Ruler of Omicron Persei 8 Join Date: May 2004 Location: Far-North Chicagoland Posts: 8,644 My Car: 2004 Prius Package: #9 Nominated 4 Times in 2 Posts TOTM Awards: 0 Friends: 18	As they've already said above, the front should always be 2 psi higher. People on PriusChat report tire pressures ranging from "factory installed" all the way up to "I don't want to scare you." At a Chicago Prius Group meeting, we sort of got a slap on the wrist for mentioning the idea of over-inflating tires for improved mileage. For that reason, we no longer promote the practice (publicly). But I can confirm, without self-incrimination, that 44 psi is just fine and within the tires' safety limit. Your roommate is nice and considerate to be concerned about your car and your safety. Take them out to lunch and enjoy that you have such a friend. __________________ Proud father of Priapus: the '04 Tideland BC9 with an OEM EV button and sense of self-righteousness >>Current Mileage<< Spreading information and passing gas in the Greater Chicagoland area

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08-28-2007, 02:28 AM	#1
Rufio24 Join Date: Aug 2007 Posts: 8 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I read somewhere on this site that the better the tire pressure, the better the mileage. My Goodyear Integrity tires say 44 psi, but my roommate said that might be too much. What is the optimal tire pressure for the Prius?

08-28-2007, 07:05 AM	#2
JimboK One owner, low mileage Join Date: May 2006 Location: Chesterfield, VA Posts: 2,060 My Car: 2005 Prius Package: #2 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 3	44 is fine, though the consensus seems to be that fronts and rears should have a 2 PSI differential due to the car's front end weight. In other words, 44 front, 42 rear. 44 is the maximum cold sidewall pressure (meaning first thing in the morning before driving) specified by Goodyear. And what you've heard about pressure's relationship to fuel mileage is correct: The higher the pressure, the lower the rolling resistance.

08-28-2007, 07:12 AM	#3
AOV Senior Member Join Date: Jul 2007 Location: Poughkeepsie, NY Posts: 303 My Car: 2007 Prius Package: Base Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I prefer 40/38, its less of a bumpy ride. Try out different tire pressures, its whatever you are comfortable with.

08-28-2007, 08:09 AM	#4
catgic Senior Member Join Date: Jul 2007 Location: HTTP 404 Not Found Posts: 223 My Car: 2007 Prius Package: #2 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	HTTP 404 Not Found

08-28-2007, 08:17 AM	#5
patsparks Uneducated bird-brain Aussie Join Date: Jul 2007 Location: Adelaide South Australia Posts: 5,853 My Car: 2004 Prius Package: Base Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 23	44 front 42 rear is good. As you said, the higher the better up to the tyres rated limit. Check tyres cold. Maybe inflate a few PSI over 44psi at a petrol station on your way home somewhere close to home then let the tyres down to the required pressure when the tyres are cold. You will need a good tyre gauge but they are cheap. Use dial type rather than stick type.

08-28-2007, 09:40 PM	#7
JimN Certified Prius Advisor Join Date: Nov 2006 Location: South Jersey Posts: 2,237 My Car: 2006 Prius Package: #3 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I'm running 45psi. "Don't tell me what it is designed to do. Tell me what it can do." The spec on the door is a negotiation between Toyota & Goodyear. The spec on the tire is Goodyear's opinion. Optimizing your fuel economy is not in their best interest. The longer the tires last, the less they sell.