First winter with my MX-5 and I’m wondering when Ill need to start washing the underside more regularly once they start gritting the roads.
It’s my daily so putting it away for winter is not an option, and I never really paid attention to this with my previous car so I have no clue how it works
I’m hoping that since the temperatures are not that low down here they are not gritted that often?
Yes, horrible thread (in the nicest possible way lol), as it means it’s that time of year. I’d have thought that neck of the woods, with not the most rainfall compared to many other parts of the UK, you’d get it (salt) even more than most places.
Where I am (west), they start putting it down earlyish November. They usually don’t for the first few ‘light’ frosts, but do so thereafter. Once it’s down, and added to, it takes decent amounts of rain to wash it away, as in hammering for a good week or so. They usually stop around April. I find that unfortunately, once they get in the habit of salting, they tend to do so even with Micky mouse frost, which they don’t do at the start of the season.
I used mine more ‘as a car’ in the first two years, and stuck the hose under at least once a week, but I did still use it selectivity and not in rain/wet etc even then.
Most people I assume will suggest undersealing it. I haven’t as it soon become a fair weather car, plus I’ve seen the process involved, and no way I’m letting someone do all of that to my car. Invariably, I find when I let people do stuff to my pride and joys, I end up with issues which weren’t there before.
Also, if your car is one to be handed back in a few years, financed etc, I wouldn’t worry about it one iota.
In Bucks there’s a X page where they publish when they grit the night before. Maybe there will be similar where you are. Interesting they seem to grit when they predict the road temp will be low enough, which may lag the air temp.
When you stop washing the underside should be after a reasonable amount to rain that will have washed the salt away after the last gritting… So that gets ‘reset’ every time that grit…
You can also experiment with Bilt Hamber Atom-Mac you can spray after a wash. Supposed to be decent against corrosion.
I’ve used it. Certainly easy to apply from a garden pump sprayer 
If Kent is anything like Northumberland…….once there’s been several early morning pile ups