Piston Slap: A Rust-free Mazda for the Current Millenia?

H.E. writes:

Sajeev,

I recently bought a 2016 Mazda6 Touring. The salesman gave me a crazed look when I told him it absolutely had to have a six-speed manual transmission. But the dealer managed to find two manual Mazda6s within about 300 miles, one of which was 45 minutes away and painted in Deep Crystal Blue paint with the black interior I wanted. I’ve put about 400 miles on it and it’s a great looking, smooth shifting car; I’m very happy.

I expect to get flamed because it isn’t brown, diesel or a wagon, to which I respond in my best Sean Connery voice, “Suck it, Trebek!”

I was aware of Mazda’s not-so-super-recent rust history before I bought it, but I’m confident (or optimistic and naively hopeful) that they’ve solved the problem. We moved to Ohio this summer, so winter, snow and salt is now an issue I’ve been unconcerned for the last 10 years.

I avoided any dealer add-ons and rust protection, but I’m curious as to whether you have any advice on how to best protect the car in the winter. Wash the underside of the car after it snows? Any commercial products I could preemptively or reactively apply? Wrap it in plastic wrap and leave it in the garage until spring? Move to Arizona? Stick my nugget in the sand ostrich-style and hope for the best?

Sajeev answers:

Yes, I am quite ashamed you didn’t get a brown one, as that’d give you instant access to The Brown Car Appreciation Society. No matter, I’ll keep my fingers crossed that new Mazdas don’t rust out like earlier models from the current millennia.

Proactive treatments preventing premature rust are numerous, but (sometimes) of questionable utility. Underside washing is a great idea, provided the water isn’t from a recycled salt bath at a shady car wash. Since many car washes use water freshened every few days, ask before you spray.

My favorite (in theory) treatment is twofold: underside coatings (Ziebart, oil, etc.) and pouring water in the external seams/gaps in freezing weather to create a protective layer of ice (that must never visit a heated garage). Spray/pour water along the rear window gaps, taillights, headlights, trim panels and — if you can get underneath it — multiple applications of H20 in the wheel wheels, especially where the quarter panel welds, folds, bolts, etc. to the chassis.

Or do nothing. Especially if you don’t plan on keeping it longer than the corrosion warranty. Nobody’s gonna fault you for doing nothing for a decade except enjoying that manual transmission and the new 6’s respectable features.

[Image: Mazda USA]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.