Ask The Expert

Your Heavy Duty Questions!

1. My owner's manual says that in temperatures above 0° F to use 10W-30 oil, but I do not see that Shell Rotella offers a full synthetic in that grade. I only see 5W-40 oil. Could I use the 5W-40 in hotter temperatures?

   Shell Rotella^® T6 Full Synthetic 5W-40 diesel engine oil offers protection in extreme operating temperatures and resists breakdown caused by heat to provide continuous protection throughout the service interval. Given that the viscosity grade reflects the range of temperatures most appropriate for a particular oil, a 5W-40 will provide both better flow at cold temperatures and increased protection at higher temperatures than a 10W-30.

   Shell Rotella^® T6 Full Synthetic 5W-40 also provides excellent protection against harmful engine wear and sludge and resists viscosity loss through shear stability to help maintain optimal pressure in your heavy duty diesel engine. Additionally, Shell Rotella^® T6 Full Synthetic 5W-40 offers enhanced fuel economy capability of up to 1.5%¹ that can save money in fuel consumption, without compromising engine protection or durability.

   Any Shell Rotella Full Synthetic or Synthetic Blend engine oil has gone through a chemically engineered process. Synthetic oil molecules are more uniform in shape with fewer impurities and better properties than conventional oil molecules. In general, synthetic oil has better extreme high temperature and low temperature performance.

   Therefore, we would also recommend Shell Rotella^® T5 10W-30 synthetic blend diesel engine oil which combines synthetic base oils and advanced additives to deliver excellent protection, even at low temperatures where the enhanced cold-flow properties help protect your engine. The oil contains Triple Protection Plus™ technology which uses synthetic base oils plus advanced additive technology to provide protection against wear, deposits and oil breakdown. Synthetic blend motor oil uses a mixture of synthetic and conventional base oils for added resistance to oxidation (compared to conventional oil) and provide excellent low-temperature properties.

2. I want to use Shell Rotella engine oil in my lawn mower, what do you recommend?

   Lawn mowers, generators, snow blowers and other equipment with a four-stroke engine can use 10W-30 engine oil in a variety of temperatures including hot summer conditions. If your lawn mower is a four-stroke engine, consider Shell Rotella^® T5 10W-30 synthetic blend which offers excellent protection, even at low temperatures where its enhanced cold-flow properties help protect your engine. As always, remember to check the oil level regularly to ensure best results!

3. Are lower viscosity oils really better for my engine?

   No matter what you put your engine through, you need to know your oil will protect your engine under all conditions.

   Viscosity refers to an oil's resistance to flow. It is the single most important performance property of a lubricant. The smaller the first number, the better the oil will flow when it is cold, protecting engine parts at low temperatures. The faster oil flows to critical parts of the engine and the more they are protected from wear.

   So, a 5W-30 will flow easier than a 10W-30 at low temperatures. And a 10W-30 will flow easier than a 15W-40 at normal engine operating temperatures.

   Additionally, lower viscosity oils can reduce your fuel costs and CO₂ emissions.

   Vehicle manufacturers and many fleets are moving to lower viscosity oils to obtain better fuel economy and help reduce greenhouse gases (compared to SAE 15W-40 engine oils). Lower viscosity oils pump more easily and help to reduce engine friction, which can improve fuel economy. In fact, high quality, low viscosity oils can provide between a one and three percent increase in fuel economy.

   Even the smallest increases in fuel economy can result in significant reductions in fuel consumption and carbon dioxide emissions. For example, every U.S. heavy duty truck increasing its fuel economy by just one percent, would see an annual reduction of more than four million tons of carbon dioxide emissions, which is the equivalent of removing more than 20,000 trucks from the road.

¹ Compared to SAE 15W-40 heavy duty engine oils.