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Can I Use Diesel Oil in My Gas Engine?

Thoughts on using Diesel Oils in Gasoline Engines

It’s common for some owners of gasoline-powered vehicles to favor diesel oils over their gasoline counterparts.

An article from AMSOIL’s Blog by John Baker

The simple answer: Yes, provided the diesel oil meets the appropriate specifications and viscosity requirements of your engine. For example, if your gas engine calls for a motor oil that meets the API SN specification, you can safely use a diesel oil of the correct viscosity that meets the API SN spec. For the typical gasoline application, a diesel oil isn’t required and the more appropriate choice is a quality gasoline motor oil for both performance and value.

The detailed answer: It’s common for some owners of modified gasoline-powered vehicles to favor diesel oils over their gasoline counterparts. Many assume diesel oils are more durable and more capable of withstanding the increased heat of a powerful, turbocharged engine. Others lean toward higher-viscosity oils to protect against wear, and it’s sometimes easier to find a 40- or 50-weight diesel oil than a gasoline motor oil. Others favor the increased detergency of diesel oils. (which is my reason for using them in my 1983 AMC Eagle station wagon BTW.)

While you can use a diesel oil in your gasoline engine, provided it meets the appropriate specifications and viscosity requirements, there’s far more to the topic than that, as I learned after talking to Mark Nyholm, AMSOIL Technical Product Manager – Heavy Duty.

Can diesel oil safely be used in gas engines?

Mark Nyholm: It depends on the specifications the diesel oil carries and the recommendation of the original equipment manufacturer (OEM). The American Petroleum Institute (API) publishes its “C” category of specification for diesel oil (currently CJ-4) and its “S” category for gasoline motor oil (currently SN). It’s common for today’s diesel engine oils to carry both the API CJ-4 and SN specifications. Though they’re truly designed for diesel applications, they can be used in gasoline applications for those customers who want to use one oil in all applications. If the diesel oil carries both specs, feel assured the oil is safe to use in diesel and gas applications. If the diesel oil does not carry the “S” category, I strongly recommend against using it in gasoline applications.

Why do some motorists favor diesel oil over gasoline motor oils?

Nyholm: There are many reasons people choose the oil they use. Since oil is not top-of-mind with many motorists, it’s typical for people to purchase based on viscosity alone. Many gasoline engines today call for 5W-30, with more and more requiring 5W-20, meaning those viscosities are typically what’s readily available. So, if you’re looking for a 5W-40 or 15W-40, it’s often easiest to find that viscosity in the diesel engine oil aisle.

Others use diesel oil under the assumption it’s a more “heavy-duty” product and must be better than gasoline motor oils. They may have been told diesel oil is formulated with special components not available in gasoline motor oils, such as more robust detergency additives to handle the soot inherent to diesel engines. In their minds, diesel oils are analogous to better protection.

Do most gasoline engines really need some of the additives in most diesel oils?

Nyholm: Diesel and gasoline oils are formulated with a variety of additives that improve wear protection, corrosion protection, resistance to foaming, viscosity retention and more. Whether the application is gasoline-powered or diesel-powered, many of the same additives are used based on what we are asking them to do in the formulation.

Now, there are additives designed to manage the byproducts of combustion, and some of those byproducts change, depending on whether you’re burning gasoline or diesel. If you’re running a gasoline engine, it’s best to use an oil that contains the correct additives to handle the byproducts of gasoline combustion. The same holds if you’re operating a diesel engine.

When should someone use diesel oil in their gas engine?

Nyholm: If your gasoline engine is heavily modified to put out more horsepower, using a diesel oil can be beneficial. It’s likely modified engines will need a higher viscosity to withstand the increased stress. You can turn to diesel engine oils for those needs or you might want to consider a racing oil, depending on your engine modifications and lubrication requirements.

Many times the engine builder will help provide insight as to what success they have found. Outside of that, if you have a bone-stock gasoline-powered application it’s best to stick with a gasoline motor oil. They are designed for that type of application and have the components required to manage that engine. Sure, you can run a diesel oil in a gasoline application; however it’s likely the formula has additional components your gasoline application doesn’t require, which might end up costing you more money.

AMSOIL diesel for gas engines

AMSOIL formulates a complete line of gasoline and diesel oils for nearly anything you have. They’re dialed in to deliver outstanding protection for their intended applications. Consult the AMSOIL product guides for recommendations for your vehicle.

Sioux Falls has a LOT of classic cars.

Some of these are survivors (never been restored) which the motors have never been rebuilt. Assuming a good amount of deposits are in the engine, have no fear – AMSOIL synthetic products are perfect. One of the things that sets AMSOIL apart is the better quality seal conditioners. It is not a fact that “synthetics cause leaks”. The issue of causing leaks simply means that the oil is not engineered and built to prevent that. It happens more frequently with conventional motor oils of average quality due to profit requirements of the stock holders. That said our HDD (Heavy-Duty) Diesel AND Gasoline Engine Oil is often the best choice.  The detergents will help clean the engine while keeping contaminants in suspension while our high capacity Absolute Efficiency Oil filters remove the problem causing deposits. Many use our High Zinc AME Diesel 15W-40 as well for this purpose as it costs significantly less. Also be sure to check out our bypass oil filtration kits.  These partial filters will remove even more deposits you will never get out through frequent oil drains alone.  Guaranteed to filter 98% at 2-microns!

So here in Sioux Falls there is a better choice for all your engines. AMSOIL’s Sioux Falls dealer at 4610 W. 12th St. or call 402-933-3902.

Thank you!

 

Sioux Falls's Towing Package – Save your Drivetrain

Don’t worry about the extra weight

Many people overstress their vehicles in the summer, pulling trailers, campers or fifth-wheels with boats, sometimes exceeding their rated towing limits. Severe-service conditions and hot summer temperatures place extreme pressure on transmissions and differentials.

Modern turbo diesel trucks and vehicles with V-10 engines boast more horsepower and torque than their predecessors, subjecting their differentials to increased levels of stress and heat. Gear oils must provide adequate wear protection, while also providing maximum fuel efficiency.

Towing made Easy with the best synthetic

Thermal Runaway

The extreme pressures and temperatures generated by modern vehicles can lead to a serious condition known as thermal runaway. As temperatures in the differential climb upward, gear lubricants lose viscosity and load-carrying capacity. When extreme loads break the lubricant film, metal-to-metal contact occurs, increasing friction and heat. This increased friction and heat, in turn, results in further viscosity loss, which further increases friction and heat. As heat spirals upward, viscosity spirals downward. Thermal runaway is a vicious cycle that leads to irreparable equipment damage and ultimately catastrophic gear and bearing failure.

The AMSOIL “Tow Package”

AMSOIL Severe Gear® Synthetic Gear Lube (SVG, SVT, SVO) and Signature Series Synthetic Automatic Transmission Fluid (ATF, ATL) provide maximum protection in demanding environments such as towing, hauling and commercial use, providing increased lubricant film protection and reduced wear at elevated temperatures.

Field Proven

Signature Series Synthetic Fuel-Efficient ATF was submitted for a field trial at an independent test facility to prove its ability to protect transmissions in the severe, high-heat environment generated in real-world towing scenarios.

A loaded trailer was towed on real highways and city streets throughout the trial. Signature Series ATF handled the punishment with ease. Throughout 115,000 miles in severe service – nearly 4x the manufacturer recommended severe-service drain interval – Signature Series ATF delivered outstanding protection for gears and clutches and maintained smooth shifts.

Severe Gear Synthetic Gear Lube (SVG, SVT, SVO)

  • Controls thermal runaway
  • Features superior film strength
  • Provides rust and corrosion protection
  • Helps reduce operating temperatures

Signature Series Synthetic Automatic Transmission Fluid (ATF, ATL)

  • Specifically formulated for severe-service towing and heavy hauling
  • Delivers reserve protection against extreme heat
  • Maintains cold-temperature fluidity
  • Superior friction durability for smooth, reliable shifts

Portland Longshoreman

On a side note Sioux Falls drivers will want to know, Lubes & Greases magazine years ago published an article about how over 100 pieces of equipment were having transmission failures in the Portland Longshoreman fleet. In particular were the Allison equipped trucks and they tried several transmission fluids and additives to see if they could improve the transmission life-span and a common downtime issue of failures under warranty. As written in the article, AMSOIL was the last one on the list (Automatic Transmission fluid – Signature Series) and since using they haven’t had a single failure since!

Be sure to ask for our Las Vegas Taxi Cab Endurance Study on the Automatic Transmission Fluids. It will amaze you or just try AMSOIL in your vehicles and start reducing downtime and save on fuel now.  If you are making payments on that truck or don’t want to have to buy the next years technology surprise, AMSOIL earns customers directly because of this knowledge of preserving the life of your drive train beyond typical ownership. And that can mean significant money saved.

Differential Stress – No Metal to Metal contact any longer!

The Severe gear in RV’s and Fifth wheel hauling trucks is known for actually netting more miles per hour on mountain roads. One customer of fame (Bobby Unser) quoted, “I switched to the Severe Gear 75W-90 and I could actually get about 7 more miles per hour out of the RV in the mountain road to our house than previously achieved.”

This is what you should expect with AMSOIL products and why our products sell!

AMSOIL Dealer
Synthetic Warehouse

4610 W. 12th St
Sioux Falls, SD 57107
402-933-3902

Premium Protection for Lawn and Landscape Equipment

Lawn and Landscape Equipment manufactures make Equipment – AMSOIL makes the Lubricants to make them Last Longer

Premium AMSOIL synthetic lubricants help lawn and landscape professionals succeed by preserving the power of their equipment and extending equipment life, allowing them to work more efficiently and save money. Extensive equipment testing demonstrates the superior protection and performance provided by AMSOIL SABER® Professional Synthetic 2-Stroke Oil (ATP) and Formula 4-Stroke® 10W-30/SAE 30 Synthetic Small Engine Oil (ASE).

Depend on AMSOIL for the premium value and performance for your equipment. OEM’s who make the best equipment are not in the business of making oils specific to their needs. Brand labeled aftermarket lubricant & maintenance products all have a catch. They must be profitable and to have application and brand specific blends can become quite costly so they are generally made with base oils which do a ‘OK’ job as long as the use is under normal stress. AMSOIL not only builds oils to exceed even the highest commercial stresses but they use only the premium base oils and additives packages available which are market specific. So the operator can have a product not only made for their equipment but will be certain it will outlast the normal expected life and them some. AND know that the AMSOIL product will even go the distance when unforeseen factors may normally render the end of the equipment life whether that be in storage, abuse or lack of maintenance.  AMSOIL Synthetics have you covered.

100:1 two cycle oil

Two-Stroke Power Equipment Testing

Carbon buildup severely affects the performance of two-stroke lawn care equipment, causing stuck rings and plugged exhaust ports and screens. The end result is power loss, smoke, rough running and hard-starting that frustrates workers, increases the need for equipment maintenance, contributes to early equipment failure and hinders the ability to efficiently and profitably deliver professional-looking lawns and grounds.

Outstanding Protection for Two-Stroke Power Equipment

Formulated with top-grade synthetic base oils, super-high lubricity and concentrated active cleaning agents, AMSOIL SABER® Professional Synthetic 2-Stroke Oil (ATP) effectively combats carbon buildup, providing outstanding protection and peak performance for the life of the equipment, keeping it on the job and contributing to the bottom line.

Preventing Stuck Rings

lawn1Following 300 hours of professional-use testing in Stihl* string trimmers at the manufacturer mix ratio of 50:1, SABER Professional kept pistons and rings virtually free of carbon and wear (see the picture on the left), while use of a leading oil brand caused significant carbon buildup around the ring area (see the picture on the right). This engine is nearing the failure point.

Fighting Exhaust-Port Plugging

After 300 hours of simulated severe use compare exhaust ports on this 2-cycle engineAfter 300 hours of simulated severe use while running SABER Professional, the exhaust-port on the left exhibited virtually no signs of blocking. In contrast, after 300 hours of simulated severe use while running a leading oil brand, the exhaust port on the right exhibited severe exhaust-port blocking. This engine barely idled at the end of the 300-hour test.

Preventing Spark Arrestor Screen Plugging

Using SABER Professional, the screen on the left did not require cleaning following 300 hours of severe-service testing.Exhaust gases flow through the spark arrestor screen (located directly on the muffler), which is prone to plugging. Using SABER Professional, the screen on the left did not require cleaning following 300 hours of severe-service testing. In contrast, using a leading oil brand, the screen on the right plugged after only 45 hours of runtime and required repeated cleaning throughout the test.

Four-Stroke Equipment Testing

Zero-turn mowers face high ambient temperatures that accelerate oil breakdown, leading to varnish and carbon deposits that stick rings and exhaust valves. This results in compression and power loss, smoke, increased maintenance and early equipment failure, all of which hinder efficiency and profitability.

Average SAE-30 oil depositsOutstanding Protection for Zero-Turns and Other Four-Stroke Equipment

Formulated with low-volatility synthetic base oils, a heat-stable additive system and concentrated carbon cleaners, AMSOIL Formula 4-Stroke® Synthetic Small Engine Oil (ASE) effectively resists oil breakdown and damaging deposits, providing outstanding protection and peak performance for the life of the equipment, maximizing productivity.

Preventing Exhaust Valve Sticking

Following 125 hours of severe-service testing in a Honda* 5 HP engine, Formula 4-Stroke Synthetic Small Engine Oil kept the valve guides in the engine pictured above left clean and functional. In contrast, using a leading oil brand, the engine pictured below left failed due to exhaust valve sticking. During engine dis-assembly, heavy deposits prevented test administrators from removing the valve.

Fighting Carbon Buildup

Pistons and rings virtually free of carbon and wear. Keeping piston ring and land areas clean is critical to maintaining the power and performance of zero-turn mowers. Following 500 hours of severe-service testing in the Kawasaki* FX 730 V engine, Formula 4-Stroke Synthetic Small Engine Oil kept pistons and rings virtually free of carbon and wear.

Sioux Falls AMSOIL – The Synthetic Warehouse – your lawn equipment lubricant HQ

We keep several products for your home lawn equipment and commercial enterprise. 2-cycle, 4-stroke, hydraulic oils, oils for hydro-static systems, water resistant grease, fuel and ethanol additives (stabilizer, intake “power Foam” cleaner, diesel fuel concentrate), tractor, skidsteer, bar and chain oils and more. Come in to Sioux Falls’s #1 Synthetic Oil Superstore and find something for all your equipment or just pop in for our informative color catalog!
Call anytime with tech questions at 800-579-0580 or the local store 402-933-3902.
We are at 4610 W. 12th St right across the street from the QT Fuel Stop and