Two new tyres. Front or rear axle?

Flatulentoldgoat

I'm tyred of part worns har har har. So I treated my car to it's first ever pair of new matched tyres.

Question is, should I have them fitted on my front or rear axle? Front wheel drive here.

Only one of my tyres is at 1.5mm and it always seems like my rear axle wears out sooner.

I'm running 175 70 14c's at 35 PSI. I wonder if I should run them at 40.

marks87

Generally speaking, it’s recommended to have the newest tyres on the rear (even if it means moving your current rear tyres to the front, i.e. if it’s the front tyres that need replacing). 

marlot

I've found that front tyres wear out at about twice the rate of rears on front wheel drive cars.

I put the new tyres on the rear, in line with tyre industry guidance.  It's slightly easier to feel/correct earlier when the front tyres lose grip.

angrycrow

If the car is front wheel drive and rears are wearing out quicker there is something wrong with the vehicle. Likely sticking rear brakes, you will want to get that checked before putting your new tyres on the rear. 

Take the car for a good run then feel the wheels, are the rear wheels considerably hotter than the front wheels. If they are it is likely your rear brake calipers are sticking.

What car is it.

Sea_Shell

marlot said:

I've found that front tyres wear out at about twice the rate of rears on front wheel drive cars.

I put the new tyres on the rear, in line with tyre industry guidance.  It's slightly easier to feel/correct earlier when the front tyres lose grip.

I'm surprised to read this (not that I read guidance from the tyre industry!), as it seems counter-intuitive to me, especially in a front wheel drive car.   The rear wheels are just "trailing", as all the drive, steering and breaking are concentrated on the fronts.

I can sort of see what they're getting at, that if the rears "go" on you, you'll be in the ditch, whereas you might get more warning or feel from the fronts as they wear.

I suppose though, in an ideal world we wouldn't be letting any of our tyres get down to a level where they start losing grip....but that could get expensive if you change them early all the time.    Be like an F1 team!!!

AdrianC

The tyre industry advice to put better tyres on the back is because of one simple fact...
Losing grip at the front results in understeer which is easy and intuitive to correct.
Losing grip at the rear results in oversteer which is far harder for the average driver to catch and correct.

Fronts transmit all the power (on a FWD car), do the vast majority of the braking, and do a lot of the cornering forces. Different cars split the cornering forces proportionately differently between front and rear, however, leading to different handling characteristics and different tyre wear front to rear.

Assuming all the geometry is correct, then if the rears wear faster, your car is using them harder. That would make me more likely to put the better tyres on the rear.

As for the tyres themselves - why are you putting commercial tyres (the C in 14C) on a car? What pressure does the manufacturer recommend? 70 profiles are very high for anything even remotely modern.

Out of this list, I'd be going for the Avon ZT7s, 84 load unless you NEED the 88 XL - or if you live somewhere rural with decent winters, the Mich CrossClimates (but only as a set of 4).
https://www.blackcircles.com/order/tyres/search?width=175&profile=70&rim=14

marks87

Sea_Shell said:

marlot said:

I've found that front tyres wear out at about twice the rate of rears on front wheel drive cars.

I put the new tyres on the rear, in line with tyre industry guidance.  It's slightly easier to feel/correct earlier when the front tyres lose grip.

I can sort of see what they're getting at, that if the rears "go" on you, you'll be in the ditch, whereas you might get more warning or feel from the fronts as they wear.

That’s more or less it.

You can also use the steering wheel to at least attempt to regain control if the fronts go; no such luck with the rears.

Ebe_Scrooge

It's always recommended to have the best tyres on the back.  Simply because, if your front tyres lose grip for whatever reason, you get "understeer", which is kind of instinctive to correct, and most drivers with a modicum of experience have a reasonable chance of dealing with it.  If the back tyres lose grip then you get "oversteer" (where the back end spins out).  This is potentially more dangerous, and certainly more difficult to deal with unless you've actually had training or practised how to correct it.

OK, there will always be exceptions, but in general, and for most "ordinary" drivers in "ordinary" cars, that's why the advice is to have the best tyres on the back.

AdrianC

marks87 said:

Sea_Shell said:

I can sort of see what they're getting at, that if the rears "go" on you, you'll be in the ditch, whereas you might get more warning or feel from the fronts as they wear.

That’s more or less it.

You can also use the steering wheel to at least attempt to regain control if the fronts go; no such luck with the rears.

Correcting oversteer is perfectly possible. It's just not quite as intuitive as correcting understeer.

Understeer - bit more lock, lift off the throttle. Line tightens.
Oversteer - opposite lock. Lifting off the throttle too much will cause problems, not resolve them.

daveyjp

Read the manual for your vehicle.  I've had FWD where it was recommended new tyres go on the front.

Moot point in my case as I always swap tyres around and change all four.

peter3hg

AdrianC said:

marks87 said:

Sea_Shell said:

I can sort of see what they're getting at, that if the rears "go" on you, you'll be in the ditch, whereas you might get more warning or feel from the fronts as they wear.

That’s more or less it.

You can also use the steering wheel to at least attempt to regain control if the fronts go; no such luck with the rears.

Correcting oversteer is perfectly possible. It's just not quite as intuitive as correcting understeer.

Understeer - bit more lock, lift off the throttle. Line tightens.
Oversteer - opposite lock. Lifting off the throttle too much will cause problems, not resolve them.

And for oversteer in a FWD car, often adding more throttle helps. In a RWD car surprisingly large slip angles can be rescued by pulling in the clutch.

The biggest issue with oversteer I imagine is people overcorrecting. Generally as the weight shifts the wheel naturally wants to go in to opposite lock anyway, but it needs good control to catch it and get back in a straight line.


I've done a fair bit of track driving and quite a lot of ice and snow track driving in Finland so I have reasonable reactions for oversteer, but even so I would much much prefer uninduced understeer on the road than oversteer.