I'm curious since to me a poly one sounds better since the factory uses a poly bumper, but I'm sure they are reasons for both.

 

poly: flexible fiber: not flexible, may crack with light impact

poly: heavy fiber:light

poly: may sag in heat fiber: won't sag at all

poly: $$$ fiber: much less epensive

 

Why would poly be more expensive, isn't it less labor intensive to produce and require less prep to finish?

 

I just painted and installed a Ruf front urethane bumper, the fit was like factory. As I was installing, I thought I couldn't imagine trying to install a fiberglass gelcoated with all that prepwork and fitting. Quality and fit are huge advantages with urethatne from a company like Ruf.

good luck

 

"Poly"........is that correct description?......guess I thought it was either ABS or urathane.

If you use fiberglass on the front of car, plan on coating it right off with a clear bra.
Road rash & dings on fiber often go through paint (to light color fiberglass).......continual touch-up.....on dark color cars not fun.

 

fiber glass is brittle and cheap to make a mold for. very cost efficient for small production runs.

poly low pressure molded is cheaper to produce but has a lot of flaws like sagging and waves.

poly high pressure mold like OEM stuff very exspensive to produce but durable and perfect.

 

yea Gregg, it's called "polyurethane" or "poly" or "urethane" all the same product. ABS is a different type of plastic.