As you probably know, the Hemi engines that were and still are very popular on many cars and trucks are now recommended to maintain with 5w20 oil. And while your vehicle is still within a warranty period, we would highly recommend you stick to that rule. Otherwise, you will lose your warranty. Yes, the oil type changes can be the reason for voiding the warranty for a vehicle.
But once your warranty period is over, can you change that suspicious 5w20 oil to something more appropriate for this engine? And why on Earth the producer claims 5w20 is a good thing for 5.7 Hemi? We all understand that the oil is too thin, especially in hot climates, and especially when you drive at high RPM.
Let's find it all out!
Why do they recommend 5w20 oil for 5.7 Hemi?
It's commonly believed that the thicker the oil is, the more friction it causes in the engine, and the more power is needed to get the engine parts moving. So, EPA rules are strict as hell and they recommend every producer to consider turning their engine to 0w20 or 5w20 oil where 20 stands for oil viscosity. But this type of oil is too thin for big engines. It's OK for Ford 1.0 Ecoboost which is the size of a milk packet, but it's really too thin for a 5.7 Hemi engine.
Ecology is the main reason why they recommend using this oil. And they don't think about your budget or about your engine longevity. It's an obvious thing that your 5.7-liter engine will have a much shorter life if it uses 5w20 oil and you still use it for towing trailers, speeding up on highways, or whatever. Everything that heats up your engine just kills it slowly.
Why is 5w30 oil much better for the Hemi?
This engine sometimes works on top of its capabilities when towing something. And the oil inside it heats up to 190 degrees or something. When you have 5w20 oil in your engine, it will be more like water in consistency.
This means the following:
- the engine parts won't be lubricated properly;
- the oil will lose its main specifications;
- the oil will fall into the oil pan too fast;
- metal parts will get intense friction and wear;
- the engine will heat up even more;
- the heat will destroy the oil even more.
This leads to a disaster with engine parts. But in most cases, the 5w20 oil will work well and will even shorten the fuel consumption which is the main reason why it's thought to be more ecological.
Is 5w20 oil recommended for all 5.7 Hemi engines?
If you are attentive enough, you can find out that this type of oil is only recommended in the US. Outside North America, these engines use 5w30 oil. And this is another reason why you should turn to 5w30 oil right after your warranty period is over or the warranty is voided for some other reason. 5w30 oil is thicker and it has better specs under high temperatures. And this is basically why it will save your engine when it experiences huge loads while towing or speeding up.
What type of oil should you choose?
If you still want to use 5w20 oil that is originally recommended for the 5.7 Hemi engine, you may want to buy the original oil that is prepared by the engine producer. Other 5w20 oil types won't be as good for your Hemi engine.
If you want to turn to 5w30 oil, just have a look at the codes written on the bottle. You should choose the oil that works OK with your engine. It's all about the additives and the components of the oil. Of course, fully synthetic oil is recommended only.
About the authors
The CarAraC research team is composed of seasoned auto mechanics and automotive industry professionals, including individuals with advanced degrees and certifications in their field. Our team members boast prestigious credentials, reflecting their extensive knowledge and skills. These qualifications include: IMI: Institute of the Motor Industry, ASE-Certified Master Automobile Technicians; Coventry University, Graduate of MA in Automotive Journalism; Politecnico di Torino, Italy, MS Automotive Engineering; Ss. Cyril and Methodius University in Skopje, Mechanical University in Skopje; TOC Automotive College; DHA Suffa University, Department of Mechanical Engineering
Add comment