5w-40 has a broader operating range than 15w-40. Unless you're penny pinching or you're misinformed about synthetic oils, it's stupid to pick the 15w-40 option. There is a single benefit to 15w-40 oils though, they will maintain their 40 weight operating viscosity longer than an oil that starts at 5w.

Whats the difference between 15w40 and 5w40?

15w40 is suitable for temperatures between -20 °C or -4 °F and +40 °C or 104 °F, whereas 5w40 is suitable for temperatures between -30 °C or -22 °F and +40 °C or 104 °F. As a result, we may state that 15w40 is better in hotter climates while 5w40 is better in colder climates.

Is 5w40 thinner than 15w40?

In general, in a given engine at operating temperature a 5W-40 and a 15W-40 have the same viscosity; one will not be “thinner” or have a lower viscosity than the other. Both will have a viscosity of a 40 grade. That cannot be said for both oils during the dead of winter.

What is the difference between 5W and 15W oil?

A 5W viscosity grade requires the lubricant to flow properly at lower temperatures than, for example, a 15W viscosity grade, so it is expected to be used at lower starting temperatures.

Can you mix 5w40 with 15w40?

Mixing a dino with a syn, a syn with a dino, a 5W-40 with a 15W-40, and so on is fine. You aren't going to get an additive clash, the different base stock of x brand of oil won't sponteously combust with the other x brand of oil that you are blending it with and make your engine throw a rod.

5w-40 vs 15w-40

What is 15W-40 oil used for?

Mobil Gas Engine Oil 15W-40 is a premium fleet engine oil specifically formulated to provide reliable protection for trucks and buses using Compressed Natural Gas (CNG) or Liquefied Natural Gas (LNG). Mobil Gas Engine Oil 15W-40 is formulated from high quality base stocks and a balanced additive system.

Is 5W40 good for diesel engines?

One engine oil for mixed fleet operations

Mobil 1 Turbo Diesel Truck 5W-40 engine oil is recommended for use in all super-high-performance diesel applications, including modern low-emission engine designs with Exhaust Gas Recirculation (EGR).

Is 5w40 good for summer?

5w30 oil is designed to operate at temperatures as low as -25°C, but is also a great choice for warmer climates that reach up to 25°C.

Is 15w-40 good for cold weather?

Even without a block heater, our recommendation is to stay with 15W40. The oils are very well formulated and flow at very low temperatures.

Can I use 15W40 in petrol engine?

Vehicle & Fuel Types

Semi Synthetic 15W-40 is suitable for use in passenger cars, 4WDs & light commercial vehicles and is compatible with Petrol/LPG (Dual Fuel), E10, Diesel (without DPF) and most other conventional fuels.

Can we use 15W-40 instead of 5w40?

YES. Lowering the first number gives you much faster oil circulation on every startup, and especially in the cold. So you engine will have lower wear on every start-up. And since it flattens the viscosity curve, in hotter areas, like turbos, a 5W-40 will have more viscosity than a 15W-40.

Which is better 5W30 or 15W-40?

15w40 is usually used in diesel engines and has a much different additives profile. 5w30 is usually used in gasoline engines. Diesel oil is designed with high antiwear additives such a ZDDP.

Can we use 15W-40 instead of 5W30?

No, you won't blow a head gasket, but 15W40 is too heavy an oil to use where 5W30 is required. Besides, most 15W40 oils are gor diesel engines.

Are all 15W40 oils the same?

No. Oils carry a certification and must be selected to meet or exceed the recommendations in your engine manual. Oil standards are normally backwards compatible, but the base oils are different.

Which engine oil is good for diesel cars?

Diesel engines are commonly rated between 15W-40 and 5W-40. The number before the W indicates the thickness of the oil when it is cold, while the number after is the thickness of oil at normal operating temperatures.

What is the temperature range for 15W40 oil?

The number "40" describes the flowability of the engine oil at an operating temperature of 100 °C. The kinematic viscosity of a 15W40 oil at 100 °C is in the range of 12.5 - 16.2 mm²/s. Engine oils with SAE Class 15W40 function in the temperature range from -25 °C to +40 °C.

Which oil viscosity is best?

For very cold weather, a viscosity rating of 5W-30 provides maximum protection. When driving in temperatures running from 0 to 60 degrees Fahrenheit, a rating of 10W-30 offers excellent all around protection. For driving in extremely hot conditions, 20W-50 oil offers the best protection.

Which engine oil is best for high temperatures?

Mobil 1 advanced synthetic motor oil provides outstanding high-temperature performance and is proven to protect at engine temperatures up to 500 degrees Fahrenheit.

Is 15w40 good for diesel engines?

ADVANTAGE 15W-40 HEAVY DUTY DIESEL ENGINE OIL can be used with complete success in over-the-road diesel trucks, off-highway diesel equipment, farm tractors, and passenger cars and light trucks with diesel, turbo-charged diesel engines, or gasoline engines and is backward compatible with previous API Oil Categories.

What cars use 5w40 oil?

The 5W-40 viscosity is a prevalent recommendation for performance engines in European vehicles with gas-powered engines, and in American diesel pickup trucks. We offer 5W-40 oils for gasoline- and diesel-powered engines. If you have a modern European vehicle, consider Mobil 1™ Formula M or Mobil Super™ Synthetic Euro.

What is 5w40 fully synthetic oil?

SynShield® OTR Plus 5W-40 Engine Oil is a premium advanced performance, fully synthetic, heavy-duty diesel engine oil formulated to provide maximum protection against wear, oxidation, deposit formation, soot contamination and aeration.

Is 5w40 good for Mercedes Benz?

Approved for use in Mercedes-Benz

It offers excellent overall lubrication and wear protection performance for all driving styles and conditions, from mild to severe. Mobil 1 Formula M 5W-40 motor oil is designed to help deliver outstanding overall performance and protection.

When should I use 5w40?

5w40 is better for starting your engine at low temperatures as it flows more easily in this environment. When the engine is running and hot, the differences are negligible; 5w40 and 10w40 both have high viscosities and are equally effective in protecting against engine wear.

Is 15w40 synthetic oil?

Mobil Delvac™ Extreme 15W-40 is a synthetic, high-performance diesel engine oil that helps extend engine life while providing long drain capability for modern diesel engines operating in extreme conditions.

Is synthetic diesel oil better?

Is synthetic oil better for my engine than conventional oil? Yes, synthetic oil is better for your engine than conventional oil. Although conventional oil (i.e., mineral oil) can provide adequate lubrication performance, it can't compete with the overall engine performance and protection provided by synthetics.