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I wonder how much pressure you should put to tyres for optimum brake distance? It seems in these above tables that higher pressure equals to shorter distance but where is the limit?I'd say not far off the manufacturer's settings TBH. These generic tests are not specific enough to be useful. As we keep saying here, each model of car uses its tyres differently. For pure stopping, as much rubber firmly planted (so sidewalls come into it) on road as possible. Which may not be the ideal for handling.
I wonder how much pressure you should put to tyres for optimum brake distance? It seems in these above tables that higher pressure equals to shorter distance but where is the limit?I'd say not far off the manufacturer's settings TBH. These generic tests are not specific enough to be useful. As we keep saying here, each model of car uses its tyres differently. For pure stopping, as much rubber firmly planted (so sidewalls come into it) on road as possible. Which may not be the ideal for handling.
Overinflated from manufacturer's settings, only centre has firm contact, underinflated, only the edges due to sidewall rigidity.
Under heavy braking, front wheels are much more heavily loaded and rears less so due to forward weight transfer, so I wouldn't mind betting that more pressure in the front and less in the rear would improve things - if stopping is your only criteria.
What those figures say to me, though, is that it doesn't make a significant difference.
Under heavy braking, front wheels are much more heavily loaded and rears less so due to forward weight transfer, so I wouldn't mind betting that more pressure in the front and less in the rear would improve things - if stopping is your only criteria.
What those figures say to me, though, is that it doesn't make a significant difference.
I wonder how much pressure you should put to tyres for optimum brake distance? It seems in these above tables that higher pressure equals to shorter distance but where is the limit?I'd say not far off the manufacturer's settings TBH. These generic tests are not specific enough to be useful. As we keep saying here, each model of car uses its tyres differently. For pure stopping, as much rubber firmly planted (so sidewalls come into it) on road as possible. Which may not be the ideal for handling.
Overinflated from manufacturer's settings, only centre has firm contact, underinflated, only the edges due to sidewall rigidity.
That is not quite true! It used to be so when tyres were not steel belted radials. But nowadays the steel belts are so rigid that overinflating (and we are now talking about some reasonable pressures, let's say less than 4 bar) will not cause any significant excessive wear, pressure just is not enough to disform the tyre. More likely cause for mid-tyre wear is acceleration, in FWD cars the fronts wear from center, in RWD rear tyres. This has been confirmed by Nokian Tyres when it was asked because we had some debate about this issue. Under inflation is an issue causing the tyre to "disform" when cornering etc resulting in wear on edges. The side walls are not as rigid as the "driving surface" of tyres.
I also know that tyres are tested with 12 bar inflation.
I tend to run my Omega saloons at 32mpg all year round, dropping slightly if we have snow.
Up to 38/45 if fully laden.
Thats bloody good considering how much you boot it about the place!
It's always wise to check pressures weekly IMO. Can save a whole lot of grief if a low tyre is spotted early. A WHOLE lot of grief... And not just under braking either.
I see almost as many under inflated tyres just by visually looking at other cars as I do wonky headlights. It's rife. And dangerous. Although those that neglect their cars also seem to generally be unaware of a cars capabilitys, which is probably just as well tbh.
Pressures are vital to a tyres performance. Depending on the tyre a few psi difference can be felt quite easily, and a few psi can be lost or gained purely on a change in temperature, ESP this time of year with generally mild weather with the odd frost, 4 or 5 psi differance is not uncommon IME. The car can feel very different then... IME.