Need car parts? Select your vehicle
Reading Time: 5 minutes
Summary
  • The average temperature of engine oil is about 240°F on gasoline engines and 210°F on diesel engines.
  • Extreme heat can cause engine oil to deteriorate. Make sure to consult your owner’s manual to know when to get an oil change.
  • Some radiators have a built-in oil cooler to help maintain the engine oil’s proper operating temperature.

Regardless of how great your vehicle is, it would not run without engine oil. To prevent your engine from overheating, your car needs oil to lubricate moving parts including bearings, pistons, rings, cylinders, and other components. Your engine oil needs to be heated to properly lubricate parts. However, how hot is too hot for engine oil? What is its usual temperature?

How Hot Can Engine Oil Get?

It’s normal for your engine oil to increase in temperature during hard acceleration. However, normal engine oil temperature shouldn’t exceed 300°F. Engine oil on gasoline engines averages about 240°F, and on diesels it runs about 210°F.

Engine oil on gasoline engines averages about 240°F, and on diesels it runs about 210°F.

Richard McCuistian, ASE Certified Master Automobile Technician

Extreme heat or cold can damage your engine. If your engine oil is too cold, it can get too thick. When that happens, it’ll be difficult for your engine oil to flow through the oil passages, making lubrication hard.

On the other hand, engine oil that’s too hot can become too thin. The oil might not have enough film strength to effectively lubricate your engine components—especially those that require metal-to-metal lubrication. The hotter engine oil gets, the more difficult it becomes to maintain good oil pressure.

Good conventional motor oil can withstand oil sump temperatures of up to 250°F, but it begins to degrade at temperatures above 275 °F. The traditional method is to keep oil temperatures between 230°F and 260°F.

A full-synthetic oil can withstand sump temperatures over 300°F, and some oval-track race teams are experimenting with ultra-thin, specially formulated, race-only synthetics that can operate at 350°F or higher.

Note that while it’s not uncommon for pickups to have a transmission oil temperature gauge as part of the instrument cluster, engine oil temperature gauges are largely an aftermarket accessory.

Oil Coolers

An oil cooler, like any other cooler, is basically a heat exchanger that allows the engine oil to transfer its heat by conduction to metal parts that are designed to convey the absorbed heat away through coolant or the surrounding air. And since heat is what travels (cold is the absence of heat), as the heat is transferred out, the oil becomes cooler.

Controlling oil temperature is crucial for high-performance or turbocharged engines. An oil pan with a large capacity and built-in cooling fins can help control oil temperature.

image of a radiator with built in oil cooler
The illustration shows a radiator with a built-in oil cooler, but there are also external oil coolers with fins. The oil that is fed to the cooler on this radiator comes from a special head that is sandwiched between the oil filter and the engine block that has hose connections carrying the pressurized oil to and from this radiator-mounted cooler. | Image Source: Richard McCuistian

Some engines, even on non-high-performance vehicles like pickups and SUVs, come equipped with remote-mounted oil coolers or filter head mounted engine oil coolers with coolant hoses connected to them.

, What is the Normal Temperature of Engine Oil?

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Saturn V8s have a narrow, heater-core type oil cooler mounted in a chamber on top of the engine between the heads so that the coolant that flows through that chamber cools the engine oil flowing through the cooler.

mechanic showing oil from the coolant reservoir
The problem with oil coolers submerged in the coolant is that if the oil cooler fails, the coolant will be contaminated with engine oil because oil pressure is higher than coolant pressure, so the oil makes its way into the coolant rather than vice versa (see photo). | Image Source: Richard McCuistian

Oil coolers control temperature with the help of coolant or the airflow that flows through the cooler.

Oil coolers mounted in the radiator tend to warm the oil when the engine is cold and cool it when the engine is hot.

, What is the Normal Temperature of Engine Oil?

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: On old air-cooled VW Beetle engines, the oil cooler is mounted in the fan shroud and plays a tremendous part in keeping the engine cool.

How Frequently Should I Change My Engine’s Oil?

Your driving style, the type of oil in your engine, and environmental circumstances all play a role. Today, a majority of auto manufacturers advise longer service intervals of 5,000 miles, 7,500 miles, 10,000 miles, or more. Our tip is to heed their instructions and make sure you use motor oil that satisfies your engine’s OEM specifications.

, What is the Normal Temperature of Engine Oil?

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: There’s also nothing wrong with shorter oil change intervals (3,000-4,000 miles) if you choose to go that route. The important thing to remember is to never start your engine if you don’t intend to completely warm it up. If it’s running too cold, get that taken care of or sludge will form in the engine even with frequent and regular oil changes.

Do Motor Oils Deteriorate?

Yes, many factors can contribute to motor oil deterioration, and one of them is high heat. High temperatures accelerate the oxidation of motor oils, especially since modern engines can reach temperatures of 235°F or higher.

, What is the Normal Temperature of Engine Oil?

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: One Ford Motor Company publication states that when using conventional motor oil in a five quart crankcase, if the oil runs a quart low, it begins to break down within 1,500 miles, so keep your oil checked and topped off with the proper engine oil.

How to Dispose of Old Oil

You should never dispose of used motor oil on your own because it is hazardous to your health and the environment. It is best to dispose of used oil in an empty, clean, and sealed container, such as an old oil container or an empty milk jug.

Drop off your old oil at your local auto shop or any other location that accepts used motor oil. These locations will then collect used motor oil and recycle or dispose of it properly.

About The Authors
Written By Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Reviewed By Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

File Under : Engine , DIY Tagged With : ,
Garage Essentials
Subscribe
Notify of
guest
1 Comment
Inline Feedbacks
View all comments
John F

A very interesting and informative article. I learned several new things about oil that i did not know.
Thank you Richard McCuistian, for another well written article.

View all Questions & Answers

expand_more
CarParts.com Answers BE PART OF OUR COMMUNITY: Share your knowledge & help fellow drivers Join Now
Copyright ©2023 CarParts.com, Inc. All Rights Reserved.