Should AMSOIL Z-Rod Motor Oil be used in modern high-performance Chevy engines? You might be surprised by our answer.

AMSOIL Z-ROD™ 10W-30 & 20W-50 Synthetic Motor OilA reader asks: I’ve got a 2013 Camaro SS and my friend has a 2009 Corvette. Both cars have the LS3 engine and have aggressive aftermarket camshafts. The catalytic converters have been removed from the Corvette, while the Camaro has high-flow cats. Both cars see a mix of city, highway and occasional runs at the drag strip. The AMSOIL application guide suggests AMSOIL Signature Series Synthetic 5W-30 for both cars. In light of the fact that the Corvette has no catalytic converters, can AMSOIL Z-Rod 10W-30 be used in it? Would it be a major problem to use Z-Rod in the Camaro as well? The cam manufacturer tells us that more zinc is definitely better for these cams.

Our answer: In most cases you should not use AMSOIL Z-Rod 10W-30 Synthetic Motor Oil in modern engines as it was designed for classic cars and hot rods. Z-Rod has very high zinc and phosphorous content to protect the flat tappet cams of older cars. These high zinc and phosphorous levels can foul the catalytic converters found on modern cars and is generally not recommended. But both of these cars are an exception.

As the Corvette’s catalytic converters have been removed, your friend can safely use AMSOIL Z-Rod 10W-30 and enjoy the extra anti-wear protection with no downside. In the case of your Camaro with high-flow catalytic converters, going to the high-zinc formula of Z-Rod may lead to deterioration of the cats over the very long term, but the trade-off is improved protection of the aftermarket cams.

Z-Rod’s higher levels of zinc and phosphorous will not have an effect on oxygen sensors or other emissions devices. Contrary to popular belief, high zinc does not clog catalytic converters, it simply causes deterioration of the internals. If your oil consumption is minimal, you may never have any issues. Again as both cars have aggressive cams and are raced occasionally, the extra protection offered by Z-Rod over modern passenger car motor oil formulas is a safe and sensible trade-off.

So while the AMSOIL Signature Series Synthetic 5W-30 is the best choice for late model Corvettes and Camaros in stock trim, you can safely go with the classic formula of AMSOIL Z-Rod Synthetic Motor Oil in some modified or raced cars. If your car is unmodified, using a high-zinc motor oil can lead to premature catalytic converter degradation and is not the best choice.

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.

AMSOIL European Formula 5W-40 Classic ESP Synthetic Motor OilA reader asks: I’ve got a 2015 Volkswagen GTI with the 2.0L turbocharged engine. I see that AMSOIL suggests 3 different motor oil options for this engine, being the European Formula 5W-40 Improved ESP Synthetic Motor Oil, European Formula 5W-40 Classic ESP Synthetic Motor Oil or European Formula 0W-40 Classic ESP Synthetic Motor Oil. Which is the best option? Also, do you offer the Mann HU6002Z oil filter for this car?

Our answer: Your engine requires a motor oil with the VW 502.00 spec for gasoline engines and all three of the AMSOIL European Formula Motor Oil products you mentioned are turbo-ready and formulated to meet that specification. But we lean toward one of these three candidates and it also happens to be the least expensive choice. That choice would be the “EFM” AMSOIL European Formula 5W-40 Classic ESP Synthetic Motor. Let us explain.

European motor oils are often categorized by their “SAPS” content. SAPS refers to an engine oil’s Sulfated Ash, Phosphorus and Sulfur content. These are vital additives that handle tasks such as wear prevention, engine cleanliness and oxidation prevention (to name a few). Some Euro motor oil specifications dictate lower SAPS levels because high levels aren’t always compatible with some emissions components such as diesel particulate filters. The VW 502.00 specification allows for high SAPS levels.

The AMSOIL Classic ESP 5W-40 and 0W-40 contain full SAPS levels. The “AFL” European Formula 5W-40 Improved ESP Synthetic Motor Oil has lower SAPS levels, but still offers exceptional wear control and performance with a sophisticated base oil and additive formula. AMSOIL is able to go “all-out” with the SAPS levels of the Classic ESP 5W-40 and 0W-40 and because the formulation is actually less complex, input costs are lower and this is reflected in a cheaper price tag.

So based on the “Full-SAPS” formula and much lower price tag, we suggest that AMSOIL European Formula 5W-40 Classic ESP Synthetic Motor (product code: EFM) is the best all-round choice for your turbo-charged VW GTI. We chose the 5W-40 Classic ESP Motor Oil over the 0W-40 Classic ESP Motor Oil due to lower cost. If you live in climates with extreme cold, the EFM Classic ESP 5W-40 has a pour point of -39°C, while the “EFO” Classic ESP 0W-40 has a pour point of -51°C. If your car is started in extreme winter cold, the 0W-40 is a great option.

As for the Mann HU6002Z oil filter, unfortunately we do not have access to that unit at this time. As our Mann product list is constantly evolving, we hope to have this unit for sale in the future.

AMSOIL makes significant upgrades to popular wholesale buying program.

AMSOIL’s Preferred Customer program has always been a popular concept. The program allows individuals who simply buy oil for their own cars, trucks and toys to buy at wholesale. The program is truly a wholesale buying opportunity for the general public and one that we eagerly promote here at Oildepot.

As much as the PC program is a great deal, AMSOIL has enhanced it to make it even better. Here are the highlights.

Occasional Shipping Discount And Product Promotions

Every so often, AMSOIL will email Preferred Customers to alert them of reduced shipping rates for a limited time or promotions on specific products. In the first impromptu shipping promo, Preferred Customers could enjoy free shipping on orders over $100.

Daily Contests For Free AMSOIL Clothing

On a daily basis, AMSOIL will draw the names of a few random Preferred Customers who made orders that day and send them free AMSOIL hats or clothing items.

Preferred Customers Now Earn Discount Points On Orders

Preferred Customers now earn a point for every dollar they spend. These points can be redeemed on future orders or membership renewals. Every fifty points are good for one dollar.

Preferred Customers can also earn bonus points for referring friends to become AMSOIL Preferred Customers or Dealers. Any referral that becomes a customer and places an order will put 500 points in the referring customer’s account.

Membership Renewal Discounts

This feature isn’t brand new, but it was introduced in the last year. Preferred Customers that enroll in the AMSOIL auto-renew program get a discount on their renewal fee. The regular renewal term is for one year at $30 in Canada and $20 in the US. Canadian members that enroll in the auto-renew program pay just $25 per year in Canada and $16 for US residents.