Hi all

As the weather gets colder and wetter, I am finding the handling on my Vitara is getting ever more exciting. There are certain corners on my usual commute where I now know I will get some gentle understeer even at low speeds. This is usually where there is a nice chunky manhole cover or a very broken surface.

As I've mentioned before, the car has tyres of variable (none very high) quality - the front two are matching Davanti. The rear are one Sumitomo and one Fortune.

The front feels pretty secure, the rear is where the action is. All tyres have plenty of tread and are correctly inflated.

I have thought the problem was the Fortune tyre, as they are certified ditch finders. However, having taken another look, the Sumitomo has a 94 load rating and the rest are all 98. Does that mean that the two rear tyres will load up unevenly, or are the load rating just maximums?

Then there's the question of what to do next. I think my options are:

1. Replace one rear tyre so that they're a matching pair.

2. Replace both release tyres with a matching, better pair

3. Replace all four tyres, probably with all seasons.

What would you do? I don't have infinite money, but I would rather not crash and die!

I would get a set of all-season tyres, put your tyre size into a reputable site such as MyTyres or Black Circles and see what prices are.

Understeer is usually due to less grip at the front than the rear. Load ratings are maximums and not usually approached with normal full loads.

Thanks. I meant oversteer.

Edited by Adampr on 21/11/2024 at 12:23

I have thought the problem was the Fortune tyre, as they are certified ditch finders. However, having taken another look, the Sumitomo has a 94 load rating and the rest are all 98. Does that mean that the two rear tyres will load up unevenly, or are the load rating just maximums?

I know this is a separate issue from the question, but I am very surprised that a car as light as the Vitara is fitted with tyres of such a high load rating.

The car* weighs 1160kg unladen (1185 for the auto) and has a GVW of 1730kg. A 98 weight rating equals 750kg, or 3000kg for all four.

For some perspective, I used 95 rated tyres (690kg) on the last two vans I used for my work, with GVW's of 2400 and 2250kg respectively. So 98's seems more than a little excessive to me and I'm curious if this is factory spec. I'd also expect the ride to be harsher than it needs to be on tyres designed to cope with so much more weight than they need to

*If memory serves, this is a 1.6 4x4?.

The front feels pretty secure, the rear is where the action is.

Have you considered swapping fronts to rear? That way you may replace the oversteer with understeer and go through the hedge forwards.

If I just swap one front to rear will they cancel each other out?