Can I use 5-30 oil in my car even if it calls for 5-20?

Question

I have an '03 Ford Focus with a Duratec engine.

Answer 1

While you can, you should use the correct viscosity. In today's engines, even slight variations in viscosity can affect the performance of your engine. If you don't have a choice, you can use it, but is it worth 10-15 bucks to take that chance?

Given that we're heading into the warmest part of the year, the differences should be less perceptible than in the winter.

Answer 2

I respectfully disagree with the stated ASE Master cerified mechanic. Ford is not the only manufacturer to use 5w-20, in fact, most manufacturers have at least 1 car product requiring the oil. It has become so common in today's cars that the price has finally become equal to that of 5w-30 at least in most larger markets.

5w-20 motor oil is used in later model higher efficiency engines. It is used due to tighter tolerances and due to it's heat dissipation qualities, as well as it's ability to reduce "dry start" conditions under very cold temperatures.

The fact is that if you are using 5w-30 instead for whatever reason, the manufacturer will not and cannot tell unless you tell them. so it will have no effect on your warranty if there is one. It is true that an oil sample can be taken through the fleet services but even those samples cannot prove the viscosity beyond the shadow of a doubt.

Should you use 5w-20 if your manual says so? YES
Can you use 5w-30 in its place in a pinch? YES

Hope this helps,

A real ASE Certified Master Technician, and an engine specialist

Answer 3

You can if you don't care about the viability of your warranty. Since it's over 4 years old you probably don't need to worry about that. Ford specs 5W20 as they fit the newer engines with tighter tolerances and feel the lighter oil gives them better cold start lubrication. If your in a warm climate like we are here in Texas it really doesn't make a whole lot of difference.

Answer 4

you can unless you are in alaska,or some super cold place.the 30 weight oil is a little heavier,but will protect a little better in super hot weather... . and if you want to extend the life of your engine,use synthetic oil.like cateroil or mobile 1 the synthetic is more expensive,but it cuts down on the wear of the engine.

Answer 5

Yes, Ford is the only manufacturer that recomends 5-20, it's barely even oil! The 5-30 will be better for your engine, they only do that to boost their EPA fuel economy rating.

Answer 6

Ask the service manager and check your owners manual. In your climate it may be appropriate. The manufacturers are putting lighter oils in mostly to increase gas mileage.

Answer 7

nope will mess up your engine big time