Opti-4 10W30 4-pack 34 oz bottles for engines up to 31hp. 

Opti-4 is the highest quality petroleum engine lubricant available, and is formulated specifically for the severe demands of power equipment. Opti-4 is a unique blend utilizing patented Eutectic additive technology for anti-wear characteristics combined with the industry's highest standard for anti-corrosion and thermal stability. Through the use of the Eutectic additive, Opti-4 extends the life of any 4-cycle power equipment engine by reducing friction, heat, and wear.

Interlube is so confident in Opti-4's ability to increase performance and extend engine life through its Eutectic anti-wear additive that when a qualifying pack of Opti-4 is purchased with a new piece of 4-cycle power equipment, Interlube will double the engine warranty on internal engine parts up to 31hp. Interlube takes the standard manufacturers engine warranty of two years and doubles it to four years (3 years to 6, 5 years to 10, etc.), twice the period of time offered by the engine manufacturer. Not only is your engine protected from wear, but you are protected from potential costly repairs for an additional two years. At the time of equipment purchase also purchase a qualifying pack of Opti-4, then simply go to www.opti2-4.com and fill out the warranty registration information.  If a failure occurs during the extended warranty period, the equipment is taken back to the servicing dealer who then files a warranty with Interlube instead of the engine manufacturer. It's really that simple. Interlube has been in business for over 35 years and has proven to be an industry leader in anti-wear oil technology.  Meets current API spec SN.

If your purchasing a new piece of power equipment, make sure to get Opti-4 Double Engine Warranty Oil protection with it.