For all of you that regularly achieve 48 or higher averages- please advise the rest of us which tire brands/types and pressures you prefer.

I am still sorting out all possible factors of difference for my 2 HCH 2006's to determine why I can obtain 49+ MPG with no particular effort on one of them yet stay in the low 40's for the other during identical driving.

 

OEM Bridgestone 381's at 60psi on my 2005 HCH-I

 

Stock Dunlops that came w/ the car....44psi

 

Thanks -
anyone tried the SUMITOMO HTR200? The local Honda "expert" likes that one and the reviews do look good. I have the std. factory supplied Dunlops too on the HCH that does great on mpg.
Goodyear eagle on "bad" car that I obtained recently, so lit ooks suspicious that those tires may drop MPG drastically ... but they have good dry/wet traction.

 

OEM Bridgestones @50psi

 

This is a true statement in AZ. Now if I driver the speed limit on the way to work in the morning at 5am on US-60 I will get 60MPG. Not that is w/o the AC on. With the AC on my MPG is reduced by 20 percent driving the speed limit. In AZ there are a few months (June, July and Aug) where your MPG will go down with the AC on. I make up for it by not using the AC in the morning (usually about 75-80 outside) and use it on the way home. Sometimes I will drive 1/2 way home (22 miles) w/o the AC on because the building I work in is about 72 degrees all day long and I like walking into a blast furnace.

 

Safety is not worth the extra 1-2 mpg you could achieve by inflating your PSI over the manufactures recommended PSI. If you have a child in your car (like I do) I can not justify the danger you are putting yourself in by doing this. Just my thoughts...but do as you wish.

 

I don't know if it is the case in your state like it is in my (Arizona) but the carpool lane is not a passing lane. If you choose to drive 45 MPH you can without receiving a ticket. Now I drive in the carpool lane at 67 mph on the way to work (2 mph over the posted limit) and I do receive some looks from time to time.

 

Kenkobra -- You state it nicely that you choose to inflate your tires to "the manufacturer's recommended [pressure]." Are you referring to the carmaker or the tire manufacturer? Depending on the answer, I see a few flaws:

1) Tires are more likely to fail due to underinflation than "overinflation." Underinflation is what caused the catastrophic failures of Firestone tires on the Ford Explorer in the 1990s. The sidewall was subject to severe deformation and failed, causing delamination of the tread.

2) The maximum PSI printed on the tires is determined by the tire company's engineering department, and contains a significant safety margin even at the higher max-sidewall pressure.

3) It can be argued that inflating your tires to the max sidewall pressure is actually safer. Higher pressures allow for a more even contact patch and more even wear across the tread. Underinflated tires will wear more at the tread "shoulders" and have a smaller contact patch. They can also be subject to more sidewall wear, as in extreme examples underinflated tires can "bend over" onto the sidewalls during turns.

4) Auto manufacturers generally "recommend" a lower tire pressure as a concession for a softer ride, not necessarily for safety. In essence, we Americans prefer our cars to ride softer, and many find the harsher ride that comes with higher pressures unacceptable. I, for one, quickly got used to the difference.

5) For me, anyway, the fuel economy increase that comes with inflating my tires to max sidewall is more than 1-2 mpg. I find it is easily more than 5 mpg for my HCH-II, which is roughly a 10% increase. That equates to roughly 50 more miles to a tank for me.

I cannot argue with your gut feeling that you feel safer remaining within a margin of safety. I will submit, however, that there is considerable difference of opinion on the matter, and that what you perceive to be safer may not apply to everyone.

Thanks for reading, and happy driving.

 

Good stuff HCHIN:


The only thing I would add is that the vast majority (if not all) of statistical tire failures acknowledged by the major tire manufacturers are ALL due to under-inflation. Their argument is that under inflation or "added load" causing significant tire hysteresis is the single most important reason for failure.
This not only contradicts the popular belief that a tire will more easily blow-up if inflated to its max pressure or slightly above but it also shows the opposite MAY be actually true.

As a last point:
Then there's the issue of heat generation. Some believe that more pressure on a tire actually makes the tire inherently hotter and leading to failure. According to the manufacturer (their representatives), the main reasons a tire will fail due to heat is because of the friction factor (likely due to less inflation) and tire flexing (hyteresis) which generates inordinate amounts of flexing/wear that leads to weakening of the tire's reinforced structural layers (whether metal, composite or fibre based).
A good TPMS will reveal that a "better" inflated tire will be a cooler tire and if the statistical reports on the accounts of the manufacturers are any indication, this tire may be much safer as well than a similar tire with less inflation.


Cheers;

MSantos