i have never owned mudguards before and would like to know from current owners does it keep some of the road crap and help avoid some of those knicks to the body from the road. i understand it may cause some drag. but would like to know is it a cosmetic part or functional part.

 

Our RX doesnt really pick up gunk behind any of the wheels.

 

If you have running boards, then you need mudguards. Mine get loaded with tiny stones.

 

I found this out the hard way, and I must agree. The running boards pick up a great deal of road grit. The mudguards help a lot. This suggests that all that grit would typically get splashed up the side of the car at speed - so I would argue “functional” rather than merely “cosmetic.” I agree with your concern about drag, but they didn’t cause any noticeable drag on my former NX 300h. I still got up to 36 MPG with the mudguards installed so it was hard to say they introduced enough drag to really matter. My best tank so far in the RX 450h was 33 MPG so again, I can’t claim they introduced enough drag to matter. YMMV

 

i do not have the running boards on my vehicle

 

Hell yes they help! I put mine on within 2 months of purchase. I had several stone chips along the lower areas of the doors. The mud guards work!

 

i dont know if that would've prevented that with or without the guards

 

How could it not? It's directly blocking a path for debris to be thrown up by the wheel and onto/across the body.

I've experienced this first-hand many years (well, decades) ago with my silver 1980 Honda Prelude. When I bought it used in the mid-to-late 80's, the lower panel below the doors had been painted a textured flat black. I drove this until late 1990 or so, and when I traded it in you could clearly see where years of debris had scored the black paint away behind the front wheels. It was then and there that I intended to have mudguards installed on all future cars, if they were an OEM option.

 

Well, you asked & I gave you my experience.

 

I know they work because it took me (2) months before I had them installed on my first RX. I had mud splashes on lower rear and didn't wait for the rock chips to occur.
Never notice a drag can't imagine a measurable affect at least on these vehicles.

 

I might just get them. But I live in the city part of pa and don’t really have much bad weather here. But I do some highway driving at least once or twice a week

 

I think I bought mine off eBay from a Lexus dealer shortly after I got my car 2017. They are still in the box. Maybe I will install them soon 🥳

 

I ordered my rx with them, so they were installed before it got to the dealer. zero regrets, they seem to work well.
the vehicle is in Minnesota, salt, sand, snow, they can only help. (sits most of the winter, used mainly for long runs to the mountains towing motorcycles)

the oe fit great

 

I am thinking about mudguards for my 2017 rx 350 but if they are so necessary then don't the engineers at Lexus know this? I'm kidding. Of course they know. Dings and minute chips to the paint can happen at all locations on the car. Would anyone recommend just the front or rear wheels for mudguards or both front and rear?

 

Mud Guards are standard in Canada and I think they are standard on all AWD models.
In my experience they ought to be used on all 4 wheels, they will reduce by a great amount the damage done by gravel, not to mention
the fact that in the rain a lot less water will be sprayed on the vehicles behind.