Taiwan seems to be tough on tyres. I think ozone, along with the sunlight and the heat, attacks them.
Mine are showing sidewall cracks, though I don’t do many miles and keep them on the high side of the recommended pressure.
Low mileage may actually be worse, since I’ve read that there’s a wax incorporated in the compound which is forced to the surface by flexion, so an idle tyre dries out.
If that’s true, waxing your tyres might be worthwhile. Whitewalls might be advantageous too, though they’d look a bit silly on my car. Subaru Casa Blanca, perhaps.
Anyway, what I actually tried was, of course, sunflower oil, the idea being that it’ll form a semi-flexible coating on the surface of the sidewall.
I’ve read a couple of (US DOD, I think) refs to SO as a rubber-protectant. OTOH, there’s debate in the diesels-on-veg-oil “community” as to whether veg oil attacks rubber seals, so the literature is inconsistent, as they say.
Pictures show outer tyre sidewalls about 10 mins after the sixth (and probably final) daily treatment with sunflower oil.
I treated the NS front tyre and the OS rear, with the other two as “controls”, selected because a dog had pissed on the OS front, so more-or-less at random, but with an uncontrolled variable, unless I can get it to piss on the other tyres as well.
The treated tyres look better subjectively, but the tyres probably varied anyway, and I neglected to take “before” pictures, which might have been informative.
The oil can be seen to be “drying” patchy, and in fact seems to soak in, which I didn’t expect. If I had, I wouldn’t have used SO, since its relatively unstable. My best guess is that, medium term, it’ll stiffen the tyre internally and actually accelerate the rate of deterioration.
Of course there is some potential for dangerous loss-of-grip here, but I think its limited. I don’t drive the car while theres visible oil sheen on the sidewall, and not usually the same day, so any migration to the tread surface should be minimal. Emergency stops tests pre and post treatment show no noticable difference.
After I did this I read that one of the big tyre producers was using SO to enhance grip, but I think that’s irrelevant either way, since they’ll incorporate it into the compound.
Front OS untreated
flickr.com/photos/31043052@N06/6900646920/
IMG_0113 by ed_lithgow, on Flickr
Front OS untreated detail
flickr.com/photos/31043052@N06/7046744391/
IMG_0114 by ed_lithgow, on Flickr
Front NS tyrewall 10 mins after the sixth daily treatment with sunflower oil
flickr.com/photos/31043052@N06/6900651372/
IMG_0115 by ed_lithgow, on Flickr
Front Nearside treated detail
flickr.com/photos/31043052@N06/6900653460/
IMG_0110 by ed_lithgow, on Flickr