Picked up a new Ford Fiesta Zetec 'climate' yesterday from our main Ford Dealers and am very pleased with it, however the ride felt a bit firm and so having driven home the 1.5 miles from the garage decided to check the tyre pressures. The tyres are 195/50 Bridgestones on R15 alloys wheels.
Using two types of pressure gauge, I ascertained that all tyres had been inflated to 41 p.s.i (2.8 bar approx.)!! I rummaged through the user's manual and discovered that, for this type of tyre size/model combination, the 'normal' pressures should be 29 p.s.i (Front) and 26 p.s.i (Rear).
Why do garages do this? Don't they know the correct pressures? I could not find any car within the Ford range that would necessitate having tyres inflated to those pressures.
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I think the clue lies in the fact your pressures should have been 29 psi but they were inflated to 2.9 Bars. Same number but a decimal point in the wrong place and wrong units used. Happened to me once in Oman; car handled very badly and tyres were 3 bars instead of 30 psi. In your case a misunderstanding at the dealer I suggest, probably perpetrated by somebody on a YTS scheme!
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I have had new cars with over inflated tyres, I assumed the factory over inflates them and the dealer forgets to check them.
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I'm no expert, but doesn't it reduce the chance of a flat spot? No excuse for not checking it before you collected your car, however.
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On subject: Historically I have slightly inflated front tyres over factory pressures finding this aided turn-in. On my 2003 V70 2.4T with the lowered suspension option, Sachs Nivomatic self levelling, and standard (for the SE) 225/45x17 P6000s, I have however reverted to standard settings. Why? Slight over inflation turned the car in to a pot hole crashing bronco for absolutely no discernable handling benefit!
On a tangent: The most fun I've ever had on (nearly bald)over inflated tyres (60psi when I asked) was in a range of front and rear wheel drive cars on a water and oil soaked skid pan training session. Brilliant fun, especially at the end of the day having a competition to catch your mate and nudge the back of their car having started on opposite sides of the track. I had the benefit of class one karting experience when it came to skid control, but this session really taught deft, gentle, smooth, control as the way to stay on the track in such a slippery environment. Less certainly was more.
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>>The tyres are 195/50 Bridgestones on R15 alloys wheels.
Phew - that's a fat and low combination for a small car. It will have a hard ride even with proper pressure in.
Remember the days when small cars like that had super sporty 'low profile' tyres of 155/70 section for the top of the range and the basic models had 145/82 section on 13" rims.
Somehow, they rode and steered better I think.
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Espada III - well if you have a family and need a Lamborghini, what else do you drive?
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Anybody know what PSI an F1 car would have...?
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F1 cars have high profile tyres and probably run at relatively low pressures although to the latter statement I have no real knowledge..
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Espada III - well if you have a family and need a Lamborghini, what else do you drive?
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"Anybody know what PSI an F1 car would have...?"
Dunno but after his death I read an artical claiming that Senna could tell if any one of his tyres was out by even half a PSI.
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My other half couldn't tell if her tyres were 15 PSI out. I once took her car out for a blast and thought the handling was appalling. Stopped at a garage and lo and behold, each of her four tyres were hovering around the 18 PSI mark. How in gods name she didn't notice I have no idea... but there you go. I now check her tyres on a monthly basis!
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Anybody know what PSI an F1 car would have...?
Of the order of 18 PSI plus or minus a few PSI according to track conditions and car setup.
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Ahhh, so my girlfriend thought her Corsa was an F1 car... that explains a lot!!
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One possibility is that the tyres were inflated first thing in the morning when the air is denser due to being cooler - in the middle of the afternoon when it is warmer then they pressure may have risen quite a bit.
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That is one explanation... however, if you knew her, you'd know that she'd just never checked them!
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"first thing in the morning"
Oh yes tha would account for all of 2 or 3psi max Not 15!
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After using the pressure settings as recommended by Audi and having the first 4 tyres wear out after 13K miles, mainly due to wear on the inner and outer bands of the tyres, I added 2-3psi over the recommendation with the new tyres. Made it to 26K and the tyres had a least another 5K in them with much more even wear. If anything the handling was better.
Fat lot of good that did - at the very least I will need a new set of tyres after my accident!
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