I have been reading about the many ways on how to increase your gas mileage in this forum. One way was to increase the air pressure in the tires. I have been getting 52 - 54 mpg since I picked up my new barcelona red IV a few weeks ago. This morning I increased my tire pressure to 40 psi front and 38 psi rear. I drove about 20 miles and found the nice comfortable ride had become harsh so I let the air out and reduced the pressure done to 38 psi front and 36 psi rear. I had the pressure at 36 psi frt and 34 psi rear originally. I will see how much the ride improved on my commute to work tomorrow. Although I want to get the best mpg, i am not willing to give up the nice ride my Prius has.
I did the same thing when I first got mine. I raised the pressure to 44/42 as recommended by many on here. It was just too harsh for me so I lowered it back to 38/36. I kept it there for a while and got used to the slightly stiffer ride. I eventually have raised it back up to 40/38 and have found that I have gotten used to the stiffer ride. I am like you, I like the higher mpg but not at the expense of a harsh ride.
What we are trying to do is balance efficency with quality of life. We need to strike a balance we can live with. I am fortunate to own a car that gives me that option.
Higher pressure also decreases the area of the tires' contact patches. how much that adds to stopping distance or affects the behavior of the ABS system is anybody's guess.
I over inflated my tires briefly (42/45) to see if it would make a difference in my mileage. I didn't notice much, and when my beloved company took "my" car in to put the wrong oil in it (it's a company supplied car) I adjusted the pressures back to OEM specs, so that the hammer swingers wouldn't notice my mischief (they wouldn't have.) Didn't see much of a decrease afterwards.....I'm getting like....55MPG. I DO see a dip in my MPG whenever somebody else drives the car. There may be a 1-2 MPG difference---I just don't see it, and I'm not going to ride around in a car whose tires are so stiff that I can run over a dime and tell you whether its heads or tails.... I have other things to concern myself with.
I find 2 psi over the recommended levels gives the best balance between fuel economy and ride comfort/grip.
I also tried increasing the tire pressure, based on info from this site. Rather than going nuts and increasing by as much as some here, I decided to try a mere 5 PSI. That lasted a few weeks. The already noisy interior got worse, and the ride quality degraded considerably. I got a few MPG increase, but it was not worth it to me, so I've been running stock PSI for the last year +.
I agree with GrumpyCabbie. Admittedly I'm not talking about a Prius, but I have found that 2 psi above the recommendation seems to be a beneficial compromise. I get slightly better gas mileage, I believe. Slightly harsher ride. Don't feel I'm compromising safety. Another benefit? At only 2 psi above recommendation, I can take my vehicle into the dealership for service and NOT worry about having to 1st adjust my tire pressure. If they even notice that I'm running 2 psi above? I can feign ignorance and attribute it to atmospheric anomally at the time I filled the tires. PS. Despite the recommendations of those that swear by significantly increasing tire pressure, I don't feel you need to worry about NOT increasing tire pressure. It's up to you, and what feels comfortable to you. I don't think you can go wrong with maintaining the manufacturers recommended PSI...Toyota's...not the tire makers...
Could be just me, but I think this would be a great thread for all non-Prius owners to chime in... I mean, all cars have 4 tires filled with air, right?
I have applied a lot of what I've learned about Prius driving to my current vehicle. Including boosting my tire pressure. In just the past two years, I think I've changed a lot about my driving style. I'm a long way from a hypermiler, but I think about maximizing momentum, which 2 years ago? I don't think I would of done. You can be sarcastic, but I think "regular" ICE cars can benefit from increased tire pressure as well as Prius. Since I know I'm in "Prius Chat" if it makes a difference, or even potentially makes a difference, I always admit in comparison that I'm not talking in my personal experience about a Prius. So yes, I'm not driving a Prius. BUT yes, I think if you are looking for a compromise that allows for the benefits of slightly "harder" tires, while maintaining many of the benefits that riding at the recommendation of the manufacturer...I'd recommend trying a simple 2 psi above.... Seems to work for at least some Prius drivers...and I find it works for me and my Honda Fit.
My Prius has never given me a cushioned ride, so inflating my tires to 50psi was no big deal. Bumps are bumps...it's no big deal to me. I'm not driving a Bentley. I bought my Prius for maximum fuel economy.
No, 100% male...who has big enough nads to live through a few bumps. Actually, I can't enough notice a difference in comfort. Funny thing, Americans, given the choice between reducing pollution and fuel consumption or comfort, will choose comfort. Latest survey reported that even with gas prices over $3.50/gallon, Americans haven't changed their driving habits.
uhh 50psi? what's the maximum allowed psi? My dad nearly died from a 8" tire explosion. Sent him to the ICU... and that was only about 30psi or so.
Sorry to hear about your dad, but according to Wayne Gerdes (Mr. Hypermiler), more flats occur from under inflating than over inflating. The maximum recommended psi rating for my tire is 48psi.
I dont think lowering my tire pressure will make that much difference in my MPG and global warming. i am getting 52-55 mpg with the lower pressure and yes..i see a noticable difference in the ride. The Prius is a nice riding car.
Well that's good and all, but I can tell you that my dad's issue was definitely over inflation. There's usually a reason for maximum ratings.. usually because a part is designed for fatigue. Now you probably won't explode the tire because its not breaching its safety factor but you could be increasing the fatigue on your tire. Whether or not you choose to over-inflate is your freedom to choose, I just hope you all consider your safety which imho is much more important than a few extra MPGs.
Hmm. I can't tell any difference in ride quality at 35 psi or 42. The dealer re-sets the psi to 35 everytime I go, so I drive home with lower pressure, and it feels like the car can't get out of its own way--but otherwise I don't feel a softer ride. Then I raise the psi when I get home and the car accelerates much better and the ride is fine. Remember, car makers freely admit that they recommend tire pressures that are lower than recommended by tire maker to make the ride softer. At the pressures prefererd by tire makers, the tire lasts longer and performs better.
