New tyres - front or rear?

nickcc

Don't know what car you have but if it's a Land Rover Freelander the tyres with the larger diameter must be fitted to the rear, unless you want a very expensive drive train repair.

daveyjp

Same with smart cars, various Mercs, Porsche, Ferrari etc etc. Very difficult to put newest tyres on the rear, which suggests advice is largely bunkum, if it were a requirement odd sized wheels would be illegal on any car.

Strider590

agrinnall wrote: »

I was going to ask if any cars built recently (last 10 years perhaps) suffer from lift off oversteer, it's not something I've experienced for a very long time.

I did come across the aftermath of it happening to a 205 GTi once, total carnage, police/fire/ambulance required, car looked like it would end up as scrap, although luckily the occupants didn't appear to have any serious injuries.

My 306 did it quite easily, but it was also something I managed easily too. You simply have to not panic, think fast, give it some gas and let the front pull the rear back into line. Of course if you crash, any witness would then say you were driving like a lunatic.....

In over steer, most folk would immediately panic and stand on the brakes, THIS is why manufacturers have made cars that won't oversteer and any that can are fitted with fancy electronics to stop it happening unless the driver chooses to turn it off.

To my knowledge the 106 and 306 (until 2001) were the last new cars on the road which would do lift off oversteer without having to really try.

Ultrasonic

daveyjp wrote: »

Same with smart cars, various Mercs, Porsche, Ferrari etc etc. Very difficult to put newest tyres on the rear, which suggests advice is largely bunkum, if it were a requirement odd sized wheels would be illegal on any car.

What prevents new tyres going on the rear for these cars? :huh: Particularly as many of these will be RWD where it's in some sense more obvious to do so.

neilmcl

Ultrasonic wrote: »

What prevents new tyres going on the rear for these cars? :huh: Particularly as many of these will be RWD where it's in some sense more obvious to do so.

I think he's referring to models that have different size wheels between the rear and fronts.

AdrianC

Ultrasonic wrote: »

What prevents new tyres going on the rear for these cars? :huh: Particularly as many of these will be RWD where it's in some sense more obvious to do so.

Staggered sizes, front to rear.

There have also been cars made with wider tyres on the front than the rear, from the factory.

Iceweasel

AdrianC wrote: »

Staggered sizes, front to rear.

There have also been cars made with wider tyres on the front than the rear, from the factory.

Yup - my summer OE wheels/tyres are 'staggered' - I have 225/45 17 on the front and 255/40 17 on the rear.

Same overall diameter because of the lower profile on the wider ones.

My winters are all 225/45 17 specifically so that I can swap them around to equalise wear.

But I hadn't been aware that there were FWD examples of a staggered set up.

Which cars are you thinking of Adrian?

AdrianC

Iceweasel wrote: »

But I hadn't been aware that there were FWD examples of a staggered set up.

Which cars are you thinking of Adrian?

Not common, true...

Citroen (who else?), at various times on DS & CX.
There was something American, too - late '80s, IIRC - but I temporarily unremember what.

Then, of course, there's been various vehicles with more wheels at the front than the rear...

jumperjohn

AdrianC wrote: »

Let the car tell you. It will, you just need to listen to it.

If it's FWD and the front end wears tyres far more quickly, and you never ever get an inkling that the back end might be nearing the limit of grip, then put the better tyres on the front - where they're clearly being used harder (hence the wear), and where the majority of braking happens.

If it's RWD, they wear roughly evenly, or the back end ever feels like it's getting loose, then back.

If it's permanent 4wd, then you really want them all to be as even as possible to save wear on the centre diff.

The theory behind "new always on back" is a massive broad-brush over-simplification, and is basically due to one simple fact - understeer is easy for those with little clue of or care in vehicle dynamics to deal with than oversteer.

If you really don't understand any of that, then the "new on rear" advice is intended for you. Follow it.

This advice is becoming less relevant. Usualy cars are now fitted with ESP, different manufacturers call it different things, so to get under/oversteer, wheel spin, aquaplaning etc etc you would have to turn all systems to off if possible.

Just change the tyres that need changing and don't worry about it.:)

AdrianC

jumperjohn wrote: »

This advice is becoming less relevant. Usualy cars are now fitted with ESP, different manufacturers call it different things, so to get under/oversteer, wheel spin, aquaplaning etc etc you would have to turn all systems to off if possible.

You're still getting it. The systems do nothing UNTIL you get it. Then, they respond to it, by cutting power and/or applying one or more brakes - and wagging an electronic finger at you, in the form of a flashing light on the dash.

If you ignore the flashing light, and get it to the point where not even the electronic safety nannies can save you from your own muppetry, then you're going to make a BIG hole in a hedge/fence/wall/bus shelter.