For use in both gasoline and diesel engines. Offers multi-functionality and wear protection. Ideal for applications where the extra protection of a higher-viscosity oil is desired. Excellent for motor homes and older vehicles, as well as many types of modern equipment and compatible with some motorcycles.
Package sizes include:
Quart Bottle
Gallon Bottle
2.5-Gallon Bottle
30-Gallon Drum
55-Gallon Drum
AMSOIL Synthetic 10W-40 Premium Protection Motor Oil is a multi-use, premium synthetic lubricant for applications that require or benefit from a higher viscosity oil. It is recommended for air and liquid cooled, large or small gasoline and diesel engines, transmissions and chaincase applications where 10W-40 oil is required with any of the following specifications:
• API SL, SJ, SH, SG
• API CI-4+, CI-4, CH-4, CF, CF-2
• ISO-L-EMA
• Caterpillar ECF-1
• JASO MA (Motorcycle)
• MAN 271/3275
• MTU Type 2
• Cummins 20071/20072/20076/20077
• Volvo, VDS-2, VDS
• Mack EO-M+, EO-M
• ACEA A3/B3, E3, E5
• MB 228.1, 228.3, 229.1
• Detroit Diesel 93K214
AMSOIL Premium Protection Synthetic Motor Oil is formulated to provide superior protection and performance in a wide variety of demanding applications. Its unique combination of synthetic base stocks and a superior additive package results in a formulation that exceeds the requirements of most gasoline or diesel applications that call for 10W-40 motor oil. Premium Protection Synthetic Motor Oil is ideal for high-mileage vehicles and high-stress vehicles subject to hot temperatures, heavy hauling, trailer pulling or off-road use. It provides the extra anti-wear protection required by engines with flat-tappet cams and high-tension valve springs. AMSOIL Premium Protection Synthetic Motor Oil offers flexibility and performance beyond conventional oils for convenience and trouble-free operation.
AMSOIL, the leader in automotive synthetic lubrication, produced the world's first API qualified synthetic motor oil in 1972. Trust the extensive experience of AMSOIL The First in Synthetics® to do the best job protecting your engine
AMSOIL Premium Protection Synthetic Motor Oil is high-viscosity oil engineered to protect against metal-to-metal contact. It resists viscosity shear and is formulated with a heavy treatment of zinc and other anti-wear additives for excellent protection of gears, bearings, cam lobes and other high-pressure components in engines and transmissions. AMSOIL Premium Protection Synthetic Motor Oil helps extend equipment life.
AMSOIL Premium Protection Synthetic Motor Oil contains no friction modifiers, making it ideal for motorcycles, maintenance equipment and other wet-clutch transmission applications. Formulated to prevent clutch glazing and slippage, it helps ensure smooth clutch engagement and long-term, dependable transmission operation. Premium Protection Synthetic Motor Oil reduces clutch wear for extended transmission life.
AMSOIL Premium Protection Synthetic Motor Oil is specifically formulated to overcome the thermal deficiencies common to conventional petroleum oils. Volatilization (burn-off), oxidation and excessive deposit formation from high heat are greatly reduced. Viscosity thickening is controlled and engines run cleaner, promoting cooler operation and long engine life in air or liquid-cooled engines.
Superior AMSOIL synthetic base stock and additive technology exceeds the requirements of both gasoline and diesel engines. AMSOIL Premium Protection Motor Oil is designed to neutralize acids, disperse soot and last longer in service than conventional oils.
AMSOIL Synthetic 10W-40 Premium Protection Motor Oil is compatible with conventional and synthetic motor oils. Mixing AMSOIL motor oils with other oils, however, will shorten the oil life expectancy and reduce the performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed. Aftermarket oil additives are not recommended for use with AMSOIL Synthetic Oils.
AMSOIL Synthetic 10W-40 Premium Protection Motor Oil is recommended for extended intervals in unmodified, mechanically-sound vehicles or equipment as follows:
Diesel Engine Service
• Normal Service - Up to 25,000 miles or one year, whichever comes first, or longer based on oil analysis.
• Severe Service - Up to 15,000 miles or one year, whichever comes first, or longer based on oil analysis.
Gasoline Engine Service
• Normal and Severe Service - Up to 15,000 miles or one year, whichever comes first, or longer based on oil analysis.
Motorcycles, Small Engines, Stationary Engines, Heavy Equipment and Other Applications
•Extend drain intervals based on oil analysis or follow the manufacturer-recommended drain interval.
AMSOIL Ea Full-Flow Oil Filters are designed for extended drain intervals. They stop smaller particles, flow more oil and last longer than regular filters. For best performance, use AMSOIL Ea Full-Flow Oil Filters and replace at the time of oil change. Other oil filters should be changed at standard OEM* intervals.
* OEM - Original Equipment Manufacturer
This product is not expected to cause health concerns when used for the intended application and according to the recommendations in the Material Safety Data Sheet (MSDS).
Click here to view the MSDS Data Sheet for AMSOIL AMO.
Keep out of the reach of children. Don't pollute. Return used oil to collection centers.
| TYPICAL PHYSICAL PROPERTIES | |
| AMSOIL High Performance Synthetic 10W-40 Motor Oil (AMO) | |
| Kinematic Viscosity @ 100°C, cSt (ASTM D445) | 14.5 |
| Kinematic Viscosity @ 40°C, cSt (ASTM D445) | 91.7 |
| Viscosity Index (ASTM D2270) | 164 |
| CCS Viscosity @ -25°C, cP (ASTM D5293) | 5638 (-25) |
| Pour Point °C (°F) (ASTM D97) | -44 (-47) |
| Flash Point °C (°F) (ASTM D92) | 230 (446) |
| Fire Point °C (°F) (ASTM D92) | 250 (482) |
| High Temperature/High Shear @ 150°C and 1.0 X 106 s-1, cP (ASTM D4683), cP | 4.3 |
| Four Ball Wear Test (ASTM D4172 @ 40 kgf, 150°C, 1800 rpm, 1 hour, Scar in mm) | 0.40 |
| Noack Volatility, % weight loss (g/100g) (DIN 51581) | 6.7 |
| Total Base Number | 12.1 |
Product Name: 10W-40 Synthetic Premium Protection Motor Oil (AMO)
Current Rating: 4.93out of 5 stars
Votes & Reviews: 44 vote(s) and 41 user reviews.
Reviewed by D: 
The absolute best of the best. I use it in everything. Every engine I use this oil in has never given me any kind of oil related problems. If you want your engines to last this is the oil to use.
Reviewed by Otis:
This oil is used in an extreme situation. Been a customer for years. No issues or failures
Reviewed by Raycer:
I changed from the boosted version which lowered my my oil pressure way to much. Now my oil pressure never drops below 40 psi. With the boosted version it dropped to the 25 psi.
Reviewed by Johnny Racer:
I've been using this oil for 10 years in my 1995 BMW 325 which is a track/race car only. I put about 2000 miles a year on it and change the oil once a year. The engine is very happy runs like a top and I have 125,000 miles on it.
Reviewed by Keith:
I'm 65 years old and have been into automotive lubricants since I was a teenager. Out of all of the Automotive lubricants I have purchased and tested over the years. Nothing surpasses Amsoil products. Unlike most, I still change my engine oils at 3000 miles. That being said, I own a 1988 BMW M5 with almost 200K miles which still runs like it just rolled off the show room floor. There are many other brands and types of oils I consider to be excellent but nothing come close to Amsoil. It's the most trust high grade lubercants I have found to date and will NOT use any other brand.
Reviewed by Robert:
I use this in my old hot rods and love it again was useing other synthetic oils but none of them are close to amszoil.
Reviewed by Kubs:
I put this in my 2002 base model Corvette, and:
-became the overall Top Eliminator at the NCCC convention 2017. (although I'm not a drag racer)
-Finished 2nd in Autocross.
-Set at track record at Putnam Park race way.
-Ran all day - two days in a row- at a track event at NCM.
with all the things to worry about when racing a street car, I can check Oil and Engine concerns off the list.
Reviewed by Roy:
My modified Subaru makes over 100 hp per cylinder so I need a very stout oil. This stuff pours like water, but has a very high viscosity at high temps. It also has loads of zinc and phosphorus which makes it perfect for high horsepower applications, turbo engines, and american hot rods.
Reviewed by Joe:
350,000 miles on 98 Chevy, started using in the 90,000, don't have to worriy about oil changes , being over due.
Reviewed by LouFa:
Previously used Mobile 1 for years, but the specifications changed over time and didn't meet the GM specs for the engine. I transitioned to Amsoil and the engine ran even quieter and I know it's getting the proper lubrications that GM intended for the DOHC LT5.
Reviewed by Voganni:
Wonderful oil for older engines that can use it. I routinely run it for years at a time in my tractor and pickup. Neither uses any oil.
Reviewed by Scott:
There are no other decent high-quality 20W50 oil products around for this price. Cannot think of a better value, at least on West Coast. Engine runs just as dependably, even out of a tire slide, as when brand new.
Reviewed by Josh:
Use this oil in an old 1975 Chevy small block racing application. Like the high zinc concentrate
Reviewed by Ed:
The filler spout is too big to fit all of my bikes cars & trucks. Like the oil.
Reviewed by Allen:
Race application
Reviewed by Scott:
Use this in my John Deere Diesel engines as well as my Chevy Trucks
Reviewed by Jeff Pease:
keeps my 33 running strong
Reviewed by JimB:
Have used Amsoil products (used to sell it) since 1974 in all of our better vehicles and farm equipment.
With annual or semi-annual changes of engine oil, never an issue related to lubrication and sludge or varnish buildup is a thing of the past.
Reviewed by Casper:
I have been using Amsoil in my cars that I drag race for 12 years...never an issue....Amsoil is by far the Gold standard of motor oils .
Reviewed by griz86:
This oil has a very strong cleaning aspect. When I drained the oil the first time I used it in a motorcycle with 17000 miles on it, it came out looking like thick almost gloppy molasses. Very black and quite thick. Subsequent oil changes have resulted in the oil coming out much cleaner. So much so that I can see light through the stream of oil as it is draining from the engine. I recently removed a side cover to inspect the clutch plates. The inside of the engine is clean like it was new. I'm very happy with this product.
Reviewed by jim:
I use this oil in my high mile Plymouth with 175k miles on the engine without any trouble with lots of highway miles. thanks
Reviewed by Robert:
I run AMSOIL 10W/40 in both vehicles a 2006 Tundra Limited, a 2012 Dodge Caravan and my John Deer 300X Riding mower and in every vehicle I have owned over the past 40 years. When 50w AVOIL was available I ran it in my 1977 Cessna 172N.
Reviewed by Buck:
Put 7qt. in my 68 Charger and I am very happy with results.
Reviewed by Mopar maniac:
Not the cheapest, just the best. After tearing down my motor after 250hr for rebuild/refresh, my rod, cam, and crank bearings still looked new. Keep in mind this isn't a pampered motor. It gets run hard, yet the rebuild seemed completely unnecessary.
Reviewed by Thomas:
I have used it in my durango for years.It is a great synthetic oil
Reviewed by Bob Barker:
I love the piece of mind knowing when I crank up my truck in the morning there's no dry starts
Reviewed by ZH:
I am a firm believer in Amsoil. This oil helped me out with my 75 chevy 350. It took away an engine tick. It also runs and idles a lot smoother. Excellent product.
Reviewed by Dirty mike_oni_gaijin:
I've been using this oil in my drift cars for years now, and have gotten to tear a couple motors down for rebuilds ( due to low compression) and got the opportunity to see that the oil has Done it's job! It kept the engin clean inside, and protected the bearing like it was supose to!
Reviewed by Dirty mike_oni_gaijin:
I've been using this oil in my drift cars for years now, and have gotten to tear a couple motors down for rebuilds ( due to low compression) and got the opportunity to see that the oil has Done it's job! It kept the engin clean inside, and protected the bearing like it was supose to!
Reviewed by Bobby:
My application is a 2013 Toyota RAV4 with 15k miles. I use 10w-40 Amsoil and change just once a year since I normally drive about 3800 miles a year anyway using Amsoil Full Synthetic..
I feel more confident using this and changing it myself the first several years as opposed to letting Toyota change it for FREE with regular oil every 6 months. Basically I can do it myself once a year and still save time from waiting around at a stealership lobby and have confidence I will not sludge up ever with better protection. Not to mention I know I do it right and tighten everything back up.
I personally had some bad experiances in the past and do not trust them working on my car since I bought it new. One time the spark plugs were apparently never tightened as an example on another new car we purchased during a service.
Reviewed by P:
I've been using this for as long as I can remember in my Land Rover
Reviewed by JGTX:
Great product and fast shipping at reasonable price
Reviewed by JimsToys:
Great product and fast shipping at reasonable price
Reviewed by Fred:
All I have ever used in my motorcycles. Runs noticeably cooler and longer between changes. Couldn't use in the old 1942 Harley though. Leaked out too fast.
Reviewed by LEE:
I have used this product for 16 years with extreme satisfaction and have always recommend the Amsoil products that I use
Reviewed by Slick mike:
I'm 60 years old and have used every possible lubrication known to man, Amsoil is by far the best.
Reviewed by David:
I use the Amsoil high zinc formula in a high reving 4cyl application . The oil pressure and temp are never an issue while on the track and I like the extra protection that the zinc provides for the camshaft and shim buckets.
Reviewed by Dan:
I use this product in my work van with an oil bypass filter along with my stock oil filter, my van has over 340,000 miles and has had the oil bypass filter since it was new and I truly believe that Amsoil has kept me on the road this long.
Reviewed by Amsoil:
I feel like a kid in a candy store, when I go to get fresh oil etc... . Thank Goodness, it's Clear as a spring day in the southwest. Amsoils #1
The Yotas Gonna Love it!. I was Surprised to see it, down the way, at a cig store of all places! Fine with me. I treat the motorr in the truck,lol better than myself!
I thought the price was Xlnt too. Yum
Reviewed by Chip:
I've tried all the good stuff - from "German Castrol" to Redline to Royal Purple to Rotella etc.
From 0w to 50w in all kinds of weather.
From the '62 max wedge Savoy to the '88 w150 roller 318 - this oil works best for my Mopars whether it's the Canadian winter or the West Texas summer.
Good pressure at hot idle, excellent flow and fast cranking in -40 (good battery helps).
My tweaked '81 high compression W150 is my daily driver and gets 13/18 mpg with non ethanol Shell 91 and Amsoil AMO.
I don't bother with UOA of Amsoil anymore, this oil is always on top.
I change the oil and filter once a year and it doesn't need topping up between changes unless I'm towing 3000 miles to TX in the summer - about a pint.
Anne & Alex Farkas give me personalized service - thanks folks!
The best dual use oil ever!
Great oil for street and track. Got my 996 oil analysis back after 6 months, multiple track days and of course...perfect results! Keep up the great work!