I have a 2010 Acura TSX, the panel was dragging, it is about 20" x 20", it was held on by 4 bolts, only one left, mechanic took panel off and said don't worry about replacing it. Is this debris shield necessary?

 

Yes it is. Not only does it protect the lower part of the car, but it also manages aerodynamics. More importantly, it is an integral part of the cooling of the engine.

Can you live without it? Yes, but it isn't good.

 

It is necessary in the same way as paint on the car, or weatherstripping on the windows. The car will run without it...but you'll also have obvious issues without it.

It was placed there out of necessity by Acura. Its useful for quite a lot of things including protecting auxiliary components, electronics, corrosion protection, aerodynamics, etc etc.

 

I personally lean toward . But I'm a bit of a minimalist when it comes to cars. I removed all the plastic from my 3G - under engine, engine bay and that stupid plastic piece that I got tired of scraping on every driveway I pulled into. I never experienced any adverse effects such as increased cabin noise, gas mileage difference, undercarriage damage, cooling issues or anything else noticeable. In fact, when it comes to cooling, most experts here on Azine remove their plastic since it tends to reduce airflow in the engine bay and insulate the heat. Remember, the Pre-Cats are located in the engine bay. Those things get hot as hell. The more ventilation the better. All that plastic is like a nice wool coat for the engine in the summer. I'm sure Acura designed the cooling system to account for that but I highly doubt it can be good to have all that plastic there. It's likely all for aesthetics. I also do a far bit of aftermarket work. That plastic gets in the way of maintenance and mechanical work. I got tired of removing and reinstalling it all the time.

I immediately removed all of it on my 4G when I purchased it as well. 60K miles and no problems.

Do what you will. If you want to keep it, go back to the mechanic to see if he still has it, then get some new bolts to secure it. Hell if I'd actually pay anything to replace it though. At most, if you're really concerned, go to a scrapyard and pick one up for pennies on the dollar compared to what the dealer would charge.

 

Do you live in a snowy or rainy climate?

 

Yes. Utah. The exhaust connections certainly get corroded. The bolts to remove the j-pipe and catback were at b!tch. However, those aren't covered by the plastic anyways. They're too hot and would probably melt it.

The items protected by the plastic, namely the oil pan, long block and transmission housing are all aluminum. So there's no significant amount of corrosion that salt or moisture is going to cause. The radiator is also shrouded by the plastic but is positioned above the front portion of the chassis so is very unlikely to be exposed to the elements.

About the only functional purpose those panels is aerodynamics or road noise. Air passing under the car wouldn't be as prone to turbulence with the plastic present vs. having all the components exposed. That may reduce noise. I personally could never tell the difference but maybe some could. Obviously, being a luxury car, Acura does what it can to reduce road noise. But protecting components? No. Anything that would cause even minor damage to cast aluminum isn't going to be stopped by a flimsy piece of plastic. You're certainly never going to find someone who had a big rock or something hit their oil pan and cause it to leak or break because they didn't have a 1/16 thick piece of plastic guarding it.

 

Road salt does corrode certain grades of untreated aluminum quite badly, actually. That white powdery stuff you see on the front of your trans/block is from road salt. It also corrodes steel components underhood (bolts, brackets, etc). Zinc plating on steel does a shitty job against salt.


Maybe you haven't seen issues, or maybe you feel the amount of corrosion and dirt under your hood is whatever you're used to. But all those parts certainly have an important purpose.

Maybe Utah's winters and salt use are not like those of the upper midwest. There is a HUGE difference in the rust/overall nastyness found under the hood of a car sans splash shields in this region (I live in the Chicago area). Some people also report failures of alternators and other electronics after someone removed the "unnecessary" plastics.

The splash shield prevents the belts and crank pulley from picking up salted slush, feces, animal parts, urine, and whatever else is on the road and spraying it all over everything in the bay.

You'd also be surprised as to how much impact a stupid piece of plastic (and aluminum, in the case of the 2G tsx) can stop...or at least slow down. The splash shield has quite a bit of stretch and tensile strength to slow something down. A bulletproof vest doesn't "look" like it would stop anything either.

Its evident that manufacturers almost unanimously feel they're needed. Splash shields aren't just on luxury cars either. Civics and Corollas have them too.

My only point is that they're not trivial or useless. They're more useful than you think. Or manufacturers wouldn't spend the money on them. R&D and fitment and the tools needed to make splash shields are HUGE money. Why would they go through the trouble if these were just throwaway items?

 

Splash shields are not limited to luxury makes. Here's one for the modest 2010 Mazda3:


It helps with mpg and noise, and keeps the engine bay clean.

That said, a friend who drives a Camry hybrid encountered bumper debris on the highway. He couldn't go left nor right, and could not come to a sudden stop. He slowed as best he could and hoped he had enough ground clearance to drive over it. Nope. It punctured his splash shield. He was dragging junk and eventually pulled over safely.

I'm thinking the splash shield is a good thing to have.