Straight Pipes

I've wondered about this myself. I'd say that it's prone to rusting out quicker if the truck's not being driven regularly, but the exhaust gases and high temps are far more corrosive than water that sits in the pipe during your 10 hour break, IMO.

Older trucks had the 'rain caps', but I never see them anymore.

 

They do rust quicker at the elbows and Y pipe after the muffler, which is why you need to cover them if the truck is not running when it's raining

 

I mean if you don't cover them all the time it's cool but when the truck sits it is important to cover them.

 

The muffler usually is fine it's always the lowest point of the exhaust which is normally the Y pipe coming out the muffler that rusts through. Rust time approx two to four yrs. Amount of rain obviously is major factor

 

All the older trucks that I've looked at have had the majority of the rust on the downstream side of elbows, suggesting that the exhaust heat is the major contributor to corrosion.

My opinion is that if you're going to sit for a week or two at a time in a rainy environment, then take precautions to keep water out. Otherwise it shouldn't be a factor.

 

Yea I always liked them but ppl were complaining because when the truck would idle the chatter up and down making a decently loud noise which customers and other sleeping truckers hated lol