AMSOIL HP Marine Synthetic 2-Stroke OilIf you’ve got a Mercury Marine OptiMax outboard engine and are looking at 2-stroke injector oil options. Let’s compare Mercury OptiMax/DFI 2-Cycle Oil with AMSOIL HP Marine Synthetic 2-Stroke Oil on both features and cost.

About Mercury OptiMax/DFI 2-Cycle Oil

OptiMax DFI 2-Stroke Oil is formulated for Mercury’s direct fuel-injected OptiMax series of 2-stroke outboard engines. The OptiMax Oil is a synthetic-blend injector oil formulated to minimize deposits and prevent wear in these high-output motors. It also contains additives to prevent rust and corrosion of internal engine parts.

About AMSOIL HP Marine Synthetic 2-Stroke Oil

HP Marine is AMSOIL’s premium 100% synthetic 2-stroke oil for direct fuel-injected outboard engines. HP Marine was formulated specially for the hostile operating conditions of DFI 2-stroke engines. This has been verified by exhaustive field testing. The full-synthetic formula reduces friction for maximum performance and fuel efficiency. The hallmark of HP Marine is clean, deposit-free operation for maximum performance and engine life. HP Marine also contains a powerful anti-rust and corrosion package for in-season and off-season protection.

Mercury OptiMax/DFI 2-Stroke Oil Why Is Mercury Optimax 2-Cycle Oil A Synthetic Blend?

Mercury has long been an advocate of using semi-synthetic blends for both their premium 2-stroke and 4-stroke engine oils. Is there a particular benefit to using synthetic-blend oils in Mercury Marine engines? The short answer is no. There is no mechanical, metallurgical or any other functional reason for synthetic-blends to be any sort of advantage in Mercury outboard engines. Mercury does not offer any sort of explanation for this reasoning.

It’s a safe to assume that Mercury uses synthetic-blends rather than full-synthetic oils because it keeps input costs down. As synthetic oils are irrefutably proven to be superior in high-performance 2-stroke marine, snowmobile and motorcycle applications, there is absolutely no other basis for Mercury to take this route. Lastly, Mercury’s literature offers that Optimax/DFI 2-Cycle Oil is graced with a “carefully modified base stock blend with a synthetic additive package”. There is absolutely no implication that this product is 50% synthetic.

Price of Mercury OptiMax/DFI 2-Cycle Oil In Canada And USA

Below is an average of suggested retail prices found at random Mercury Marine dealerships. Prices may vary in your region. Mercury OptiMax/DFI 2-Cycle Oil is sold in 4-litre and 10-litre containers in Canada and 1-US gallon (3.78L) and 2.5-US gallon (9.45L) jugs in the United States.

Canada (CAD$)

  • 4-litre jug- $60.78
  • 10-litre jug- $140.44

United States (USD$)

  • 1- US gallon jug- $43.85
  • 2.5 US gallon jug- $95.22

Price Of Mercury OptiMax/DFI 2-Cycle Oil Versus AMSOIL HP Marine

AMSOIL prohibits us from publishing their wholesale prices, but we can illustrate on a percentage basis how the price of AMSOIL HP Marine Synthetic 2-Stroke Oil compares to Mercury OptiMax/DFI 2-Cycle Oil. The AMSOIL HP Marine pricing data below is based on wholesale prices when purchasing a full case of 4X1 US gallons with average shipping charges included. Remote destinations may have extra shipping charges. HP Marine comes in US quart and US gallon formats and beyond that, they step up to kegs and drums.


  • 4-litre jug- OptiMax/DFI 2-Cycle Oil costs 60% more than AMSOIL HP Marine
  • 10-litre jug- OptiMax/DFI 2-Cycle Oil costs 42% more than AMSOIL HP Marine

United States

  • 1- US gallon jug- OptiMax/DFI 2-Cycle Oil costs 50% more than AMSOIL HP Marine
  • 2.5-US gallon jug- OptiMax/DFI 2-Cycle Oil costs 40% more than AMSOIL HP Marine

Again, the AMSOIL prices in this comparison are based on wholesale prices when purchasing a full case of four gallons and include average shipping charges.


Consider that AMSOIL’s HP Marine 2-Stroke Injector Oil is a full synthetic formula that is designed to be safe and highly effective in the newest DFI 2-stroke engines. Yet it costs considerably less than the synthetic-blend Mercury OptiMax/DFI 2-Cycle Oil found at boat dealers. In our opinion, AMSOIL’s delivers legendary quality and is a great value at any price. The quality of OEM oils tends to be adequate, while the price tag tends to be anything but. Just because Mercury puts their name on the jug does not mean that it is the best oil for your engine.

Contact us for a wholesale price list using the form on this page or call us at 1-800-748-5781 and we’ll show you how easy and cost-effective it is to upgrade your Mercury OptiMax outboard engine to AMSOIL HP Marine Synthetic 2-Stroke Oil. We ship from warehouses in Canada and the United States.