Oil for Generac GP5500

[NormanBuntz]

My Generac is a different animal: propane powered 13K whole house unit that's 7 years old. In my early oil changes using 5w-30 synthetic blend, I noticed more oil consumption (like 2/3 qt every 20 hours operating time). Since the 3rd OC, I've used Napa 5w-30 full synthetic with much less consumption. Whatever viscosity you choose, I say to stick with full syn.

 

[repairman54]

Running M1 0w-40 in my 10k propane unit. Need that 0 for -30 deg. below starts at my camp. No issues on it's first winter, starts everytime, exercise or outage. Battery heater on the battery also. It's on a thermo cube, on at 35 deg. off at 45.

5-30w synth. in my manual start 10hp 5600w unit on a -15 morning you would lift it off the ground pulling the recoil. 25 hard pulls to get it to fire. 0-40w onboard, 4-5 pulls and running.
Synth is a must in any air cooled motor IMO

 

[MikeinNY]

Originally Posted By: repairman54
Synth is a must in any air cooled motor IMO


Agreed 100%

When I got my first generator (powermate) I remember lifting that thing off the ground trying to pull start it in low temps with straight 30 in it (I did not know much about importance of air cooled engine oil choices at that time and still learning today.

I know my Generac seems to like the M1 TDT but I'm getting the urge to try some other synths. Researching different oils is like an obsession right now.