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My daughter's new Corsa mentions ECO tyre pressure settings in the handbook. They are about 10 psi above normal and provide lowest rolling resistance. Trouble is, handbook does not mention when or if the tyres should be inflated to these pressures. Does anyone have an answer?
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From memory, normal Corsa C tyre pressures are 32 psi front & 26 psi rear for the smaller engines so I guess if they want you to go to 10 psi over that would be all the time with no increase in pressure for fully loaded.
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42 lbfsq"? Wouldn't fancy that on a greasy road.
At least you could put any fuel saving towards the new tyres and the bodywork repairs.
Is this nonsense GM's way of inflating their official fuel consumption figures?
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Sounds high, but should be fine as long as tyres have a few hundred miles to "bed" in at those pressures. I always run my car tyres hard - both my old Clio (shed) & Vectra B get 36 ish lb's. Clio especially benefits, handles much better, dry, wet or greasy roads. Vectra doesnt seem to handle whatever I do though.
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Sounds high but should be fine as long as tyres have a few hundred miles to "bed" in at those pressures.
At which point you shorten their life because they'll wear quicker in the middle. And until they're "bedded in" you also lose traction as you're not getting 100% contact with the road. Vectras don't handle, they just sort of flop about and give you absolutely no feedback whatsoever. Take the wheels off and it'll drive exactly the same(!!)
Personally I'd stick to the manufacturer's standard tyre-pressure. Usually somewhere around 30psi does the job.
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I think this 'wear in the middle' is a myth, certainly with modern radials with several belts under the tread. I've tended to run my cars somewhere between 'normal' and 'full load' pressures even though the car rarely has more than one or two passengers. I've always thought this prevents them ever being too low, and given that the 'normal' pressure is designed for comfort and not handling. Never yet seen any extra wear in the centre.
JS
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Never yet seen any extra wear in the centre.
I have. OK, they were narrow 155/80R13s, but a well-known tyre chain over-inflated them, and after 12k they were almost bald in the middle, with a good 3mm left at the edges. Maybe with modern cars having much wider tyres it's less of a problem, but it's not a myth.
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a well-known tyre chain over-inflated them and after 12k
Is it common practice not to check tyre pressures for 12K miles?
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Is it common practice not to check tyre pressures for 12K miles?
Well they were all the same pressure - that was enough checking for me when I was 18! Current car actually has a sticker behind the driver's door with all the pressures written on it, so I've got no excuses now. Still, it's not a myth that tyres wear in the centre if they're over-inflated. Likewise it's not a myth that they blow-out at speed if they're under-inflated.
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I think this 'wear in the middle' is a myth
RWD cars tend to wear the rears in the centres and the fronts at the edges - MB's are noted for it and it''s common practice to run the rears a couple of pounds under the minimoum pressure and the fronts a couple of pounds higher to try to prevent it.
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Bill
This sort of wear is a result of the suspension design; shortish swinging arms - as an another example Ford XR3is were well known for wearing the rear tyres in the centre. I'm not convinced a couple of psi pressure difference will greatly influence this.
JS
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I'm not convinced a couple of psi pressure difference will greatly influence this.
It certainly helps.
Allegedly it?s something that?s common in all powerful RWD cars ? mine is not hugely powerful (C270CDi) and the majority of its use is steady speed motorway cruising. The rears on the first set of tyres were bald in the centres when they still had 3-4mm at the sides and had to be changed at 20K (and that was later than it ought to have been).
Adjusted the pressures on the replacements and they?re wearing evenly after 10K miles.
I'm struggling to think how a FWD car like an XR3i could wear its rear tyres in the centres (other than by them being over-inflated).
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Bill
Believe me it was a well known 'problem'! Seen it on several examples. As I said I believe it's an effect of the suspension on the Escort. They incorporated relatively short transverse suspension arms, which produced significant laterally movement of the wheels as they moved up and down. The XR3i's seemed worse than the standard cars because of their wider tyres.
JS
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Dr Chris
What engine is this Corsa-D; are the rims factory-fit and what size tyres are fitted?
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This is a new shape Corsa Design 1.4 with factory fit alloys carrying 195/55R16 tyres. Normal pressures are 29psi front, 26psi rear but ECO pressures are 10psi higher front and rear. Fully loaded pressures are 38psi front, 46psi rear.
I think we'll just stick to the normal pressures myself. Might ask the dealer if we go there at some point.
BTW, shows how much dealers bother about tyre pressures, car was delivered with all tyres at 31psi (roughly!).
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this can't be right surely? My 205/65/15 tyred MPV's book only recommends 41psi at the rear when fully loaded ie 8 people and their luggage on a motorway run.
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It will be right to increase the fully loaded pressures to that level. It is about the relative increase in load on the rear tyres, not the actual increase. Loading up a small 3 door hatch puts a relatively much higher load on than loading up an 8 seater mpv.
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What tyres are on it?
Daughters Colt has Conti EcoContacts (and same tyres were fitted by VAG on other daughter's Ibiza when originals wer replaced) and they run on 'normal' pressures.
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Yes
These are to minimise the rolling resistance and therefore maximise your MPG.
I wouldn't bother.
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