Re: Lower vs higher
figgy said:
Aren't you going to get more traction with the lower inflation, so that if you have the front lower than the back, if anything at all happens the rear might slip more than the front, which would in fact compensate a bit for the front slipping if at all during acceleration or oversteer types of situations?
i used to assume the same idea. that lower pressure = more contact patch eg: better traction...
i dunno, i guess technically you could have more contact patch, but how much really... , not mathematically really, but effect after all the factors of reality come down really... one has to be aware that reducing tyre pressure is probably going to have side-effects which will occur at a greater rate of increase than the rate of increase of contact patch as pressure decreases. also, consider that at 3 PSI, the tyre is going to have a very large contact patch but will probably be crap to use, assuming it even holds the car above the rim.. i know that is over-example, but at least 83% of what comes out of my mouth is opinion, 40% of the time. <G>
i can say that i used to run my tyres in my civic a bit lower than spec, for precisely that methodology -- but since browsing this forum, i, on a whim, decided to take them up over the tyre spec. got an aircompressor and a dialgauge for my b.day; and now i've got the fronts in the civic running at 50 and the rears at 46 ( cold, both ways ), and the handling kicks the pants off of what it was when i had them running under spec ( ~38 all around - tyre says max PSI is 44 -- not seeing any uneven treadwear so far, been pumped up since middle of march ).
absolutely annhilates it.
i'm going to change to running 46 up front and 50 in the rear, perhaps tomorrow, and i'll see how that feels; but fwiw, i'm probably never going to under-inflate my tyres again for the idea of more contact patch.
seemed to make the sidewalls as stiff as oatmeal when they were underinflated... real squodgy. that sucked 8x more than any improvement by having a centimeter or so more diameter of contact patch.
i would offer that for any situation you mention slipping, you're really feeling the car leaning against the tyre, and the car winning because of the sidewall rigidity, but i cannot say i have driven an insight more than once, so i'm just worth conjecture at the moment.
-edit-
oh, yeah, they're toyos on the civic too., i just noticed you mentioned that, figgy.