Different tyre variants on front wheels.

In news:4vhic.34774$ snipped-for-privacy@stones.force.net, Gary McClean decided to enlighten our sheltered souls with a rant as follows

I doubt it'll make any noticable difference at all. Focii are quite tyre sensitive, but not to that extent.

With ABS you should have the same tyres on each axle.

Two on the front the same and two on the back the same :)

I'd go and find a wet roundabout, put my toe down and see if it made much difference to how / when it let go. I've had combinations of s**te tyres get nasty, but Goodyears might behave differently.

The message from "Tim Anderson" contains these words:

Out of interest - why is this? I'd have though it was less critical with ABS which after all is supposed to prevent skids than with manual (pedal!) braking in which a mismatched tyre could break away sooner leaving the driver to cope with a skid on their own.

If it was me I would go back and ask for a pair, that is after all what you wanted.

Personally I'd go back to the dealer and get a matched pair. Maybe I'm over fussy, but no way would I accept a pair of new mismatched tyres. I suggest you insist that they change one tyre to match the other. Exactly. Both tyres on each axle should be the same IMO, ideally with the same degree of wear as well. More so, as far as wear is concerned with the driving wheels, than the others. In fact it probably wont make much difference, but no one would convince

Thanks for the advice everyone.

I went back to the dealer and explained the situation and had one changed. It was the first they'd heard of the different variants. Though how the fitter didn't notice it, I don't know!

Later on, Goodyear phoned back in reply to my email. They said they strongly recommend that a three rib and a four rib NCT5 are not fitted on the same axle.

Gary.

You did right there IMO, but different tyres on the same axle is OK if they're same size and both radial (which all tyres are these days). However, the other day I was overtaken by a Volvo S60 going ~80mph on the motorway. What's so odd about that? The Volvo had a tiny space saver on one of the front wheels!

It wasn't me - although I've got sport contact II on the front and NCT5 on the rear (fronts about to go to NCT5 in about a thousand miles I guess)

The old fashioned tyres were cross-ply. Do they still use them? I remember they were used on RR as they gave a smooth (but wallowy) ride.

I disagree. Different makes, despite being the same size and type, can have different characteristics, that make them behave in different ways. In particular they could have different grips, different slip angles, and different flexing properties. Any of which could affect the cars behaviour in extreme circumstances. Hard braking, cornering etc. I'll accept that those differences might not be noticeable under normal driving conditions, indeed the law makes no distinction, but the fact remains that it is preferable, and safer IMO, if both tyres on the same axle are identical. Mike.

The message from Rob contains these words:

No, I don't think so. They've passed EU type approval so should be street legal provided they're used within the manufacturer's ratings - which like I said include a speed limit.

----- Original Message ----- From: "Mike G" Newsgroups: uk.rec.cars.maintenance Sent: Tuesday, May 04, 2004 3:00 AM Subject: Re: Different tyre variants on front wheels.

Hmmm. I seem to have missed all the comments added after I made my second post saying I'd got it sorted. Many thanks to everyone for their opinions. I do in fact have two different brands of tyre on the rear of the car due to a minor mishap last year, but for the "business end" I am always more wary. The car is a Focus TDCi and I do enjoy driving it to it's potential when traffic allows. Surprisingly, I got a year and about 19,000 miles out of my last set of NCT5's, and they were only down to 2.5mm too... so that's why I was particularly keen to get them again! I changed them cos I'd rather have good tread depth for wet conditions.

On the point of space saver spares, the Focus has one and it says 50mph max on it for as short a distance as is neccessary in the handbook, though I've never had to use it so far.

Gary.