Quote:
Originally Posted by RedDevil
When I raised the pressure in my tires from 30ish to 45 PSI I noticed that my daily commute distance as indicated by the MID dropped from 36.4 km to 36.2.
A higher tire pressure apparently makes the tire cover more distance per rotation. It gave over 5% better FE, and I can add another 0,55% to that to compensate for the difference in circumference.
It will also make a difference on the ratio between indicated and real speed.
So if you were measuring acceleration by the speedo, MID or SG, here's your answer. Though the difference between 45 and 55 PSI will probably have less effect than the 0.55% I got from raising from 33? PSI to 45.
If you were measuring your speed by GPS; nothing said  |
Thanks, I do believe you that you get more FE at 45 than at 33 with that tire/car combo. I was using the ScanGauge to monitor the engine load and I could tell without looking at the speedometer that the car was accelerating quicker at 45 PSI and a LOD of 15 than above that. But, I see it as this:
Perhaps it's not raising the pressure in of itself that raises fuel economy (Though that helps with under-inflated tires,) But keeping close to just the right pressure for that tire and vehicle combo is it; Too low, The engine works harder. Too high, The engine works harder. Kinda like Icarus, Except Icarus died from flying too high. (Keep that in mind if over-inflating tires and I speak not only to you here; Over-inflated tires just as under-inflated tires are more vulnerable to a number of things that could put a driver and others in danger plus premature wear on the tires but don't take my word for it, Web Search it.)
And some vehicle and tire combos may be best set at 35 PSI, Some at 44 and some at 50. The number doesn't matter as long as the tires are "Tuned" right for that particular car and tire combo, Like tuning and then intonating a guitar. So what I'm saying is, "Keep in tune for the most efficiency."
(Edit, 2013-September-18: What does it profit if I'm trying to sound wise if I am not?)