Stiffer rear engine mount causing dash to buzz

[Henry VIII]

The previous owner of my recently-purchased 2014 5-speed Focus SE installed an aftermarket "stiffer rear engine mount."  He was vague about what the benefits were supposed to be, but contended the car felt somehow 'better' afterwards.  I am an older, milder driver and am in the habit of short-shifting unless I'm in a hurry, and not changing down to 1st gear when going round corners if the car is carrying adequate speed, preferring to use 2nd.  I have done this for years with a multitude of cars, including several Porsches and Ferraris.  My issue is the Focus' dash 'buzzes' badly when under load at low RPM in those circumstances, which is annoying and I think will encourage future looseness and rattles.  I'm thinking of installing a new original-equipment mount that should have more flexibility and better absorb these vibrations.  Do any members have experience with these stiffer mounts?  

[JW1982]

Which type of engine do you have? In Europe only the 85 HP, 105 HP and 125 HP 1.6 TI-VCT engine and the 100 HP version of the 1.0 ECOboost engine did have a 5-speed gearbox.

Vibrations under load at low RPM's are usually the result of not enough engine torque at the particular engine speed. This is especially a known symptom on lower powered non turbocharged engines. The only way to prevent this is shifting down a gear and keep the engine at somewhat higher RPM's.

The rear engine mount is officially called torque restrictor. The purpose of this mount is to limit the rolling movement of the engine/gearbox. The original torque restrictors from Ford are know to be quite soft and allow quite of bit of rolling movement of the engine. The advantages of a stiffer torque restrictor are less wheelhop (expecially at higher powered vehicles) and smoother gear changes because the engine has considerably less rolling movement during gear changes. The disadvantages of a stiffer torque restrictor are increased vibrations (usually at idle). 

A well know upgrade is the torque restrictor of the Focus Electric which is a lot stiffer than the torque restrictors that are used on other engine types but not as stiff as some aftermarket torque restrictors.

Be aware that the Focus MK3 engine mounts are known to wear pretty quick. The engine mounts become softer (especially the oil filled mount) which affects the dampening characterictics of the mounts. This usually results in increased vibrations and increased rolling movement of the engine. This is a known problem (even on low mileage vehicles). On a 2014 vehicle it is not a bad idea to just replace all engine mounts.

[Henry VIII]

Thank you for your informative reply.  My US car has the twin-cam 2.0 engine with direct injection, normally aspirated, with 160 HP and 146 pound-feet of torque.  I would have thought that would be adequate to pull 2nd gear on light throttle at 25 mph.   The car has 92,000 miles at present, and the upper mount on the right inner fender appears to be in good condition.  The previous owner did comment on trying to limit the engine's movements, as you explained are considerable with stock mounts.

When at idle there are light vibrations audible, but not felt.  Perhaps I should consider simply replacing all three mounts with original Ford parts to get my 'buzz' under control.