Just saw some ads about custom made engine mounts using polyurethane.
factory engine mounts using rubber.
?
Just wanna know any major difference between these two? any effect for engine vibration?

poly last longer but with the price of stronger vibration. rubber last not as long but more compliance with vibration absortion

With poly, you can feel the road more than rubber. Not so suitable for family car. Also for the 2-3x the price of poly compared to rubber, I would rather stick with rubber as I have extra money to change when it's time to change.

However, there are people who says after change to poly, vibration is not really that bad and they get better handling. So I guess it also depends on the car.

Engine mounting la. Not drive train bush.

I had poly for my VR4. Full set including engine and gearbox. Car vibrate like hell.

After drilling 9 holes for the gearbox mount, the vibration went away. Only slight vibration during idling in D now. Not too bad because the mounts already 8 years old.

first time hear can drill holes thru mount!!!

seems legit and can lessen issue

poly are usually full and solid right, rubber ones some have some space between rubber

The shop owner told me cannot drill or it will crack. Mine already 8 years old so I have proven him wrong. Then again, I don't do track or drive on bad roads. Mostly highways or flat roads.

edit

This post has been edited by croydon: Nov 22 2019, 05:09 PM

Well..another way to do it is don't drive like a bull. The mounting and all will be in good condition.

poly is stiffer so transmit more vibrations

If want performance solid welded mounts

To compare OEM rubber style and poly, poly will definitely feel harsher at idle.

Engine Mounts bushing do comes in various forms.
OEM style, full rubber, OEM + PU from windscreen for DIYers, Poly, Teflon and Solid.
You can google them to understand them.

Mine rear engine mount is OEM + windscreen PU, sidemirror are shaking at idle, steering very minor vibration but the steering rack are solid mounted.

polyurethane is squishy plastic, a bit like your food packaging.

They do not last longer than rubber, and can wear quicker if too much stress is given. Unlike rubber they do not harden so you do not get vibrations over time, but isnt as good as rubber at absorbing vibrations. Therefore it wears based on how much force is given to it vs rubber which wears from age instead of use for this case.

Theres a reason why the region of force where an object deforms permanently is called the plastic zone.

So can consider for lighter engines or more balanced engines that you rarely drive.

What am I reading ??
Polyurethane for engine mount ??

The hardness reading is totally different la.of course it's gonna transfer all the vibrations into cabin