Read somewhere that a jet wash was a) the best way to keep winter salt off a car underside and a good way to get grime out from under the wheel arches.

However

a) It can get water into places where water ought not to go.

I have heard it can damage tyres.

Any thoughts?

On point a), I recently arrived at an un-named garage to take a test drive, only to be told that they had just hosed the car down and now couldn't get it started. Bit of a deal-breaker that.

Ive always jet washed cars (Not ramped up) in winter and had no problems with the tyres etc. the local council were still salting the roads even though it wasn't freezing and was taking the car to the jet wash every week.

Every spring, I ramp up the car and wash the underneath and the engine bay, making sure anything electrical etc., is covered up (Tin foil is good stuff for this).

Maybe the garage had just washed out the engine bay without covering anything !

Edit

Notice your from Notts ! Did you notice how much salting was done last year !! The roads were covered in a thick white dust when it was dry, not very nice to get inside your mechanicals.

I use one everytime i wash my car. A bit of common sense and you'll be fine. Give me a glass of water and i could make an engine not start.... :P

I always jet-wash, never had any trouble at all. Dunno where the "it damages tyres" comes from though, thats very unlikely!

the tyre shine stuff does more damage to tyres than jet-washing

jet washing under the arches has got to be a good thing , to remove all the mud and debris that has stuck under the lip

a) Rubbish

Even more rubbish

Thanks all. Seems pretty conclusive.

I've always had my car washed by Jet-Washed. Infact, i want to buy a Jet-Wash, but i cannot see the difference between Karcher's own, which start at around £100, or buy a decently powered one from Halford's own make for around £40?

They're good for clearing all the muck off though.