If in the owners manual it says I should use 5W-20 motor oil, can I use 10W-40 motor oil instead?

I have a 2009 Honda Fit. I just recently bought 10W-40 and when I got home to put oil in the manual said 5W-20. What's the difference? And is it okay if I still use the 10W-40?

C'mon Dude… It doesn't say use the wrong oil anyway! It says use 5w-20w! The thicker oil will mess up the lash adjusters and plug up the VVT actuator. Go ahead and be stupid! I still can't figure out why people think the experts don't know what they are doing when they list what is needed!

You CAN, but it's NOT recommended.

The difference is: IT'S DIFFERENT, and it's NOT recommended!

Why didn't you read the manual FIRST? I recommend that you return to the store and exchange the oil for 5W-20. It's simple enough.

The 10W-40 is a thicker oil. Do what the manual recommends. The engineers don't make you service the car their way for no reason. And in the future, if you feel like the dealer is ripping you off, look at what the engineers ask of you in the manual and compare it to what the dealer recommends.

You will be OK if you only added a little to top it off, use the right stuff in the future.

ADD: Don't let these so called gear heads fool you into thinking it will ruin the engine, just service it with the proper oil at the next service and it will be fine. Adding a pint or two of slightly thicker viscosity oil to a 4-5 quart sump will not hurt the engine unless you live in arctic conditions. Older engines actually need the thicker viscosity as they age with bearing wear to keep good oil pressure at low RPM's. The reason it's called muli-weight oil is because they add long polymer chain additives that expand and contract with temperature, 5 or 10W oil is just that with chemically derived temperature coefficient molecules added that stretch out thin when they are cold and contract/coil up when they are hot like a child's slinky spring when you coil it to emulate the higher weight oil at operating temperature.

The best lubricants used in deep space vehicle applications are still made from whale oil to this modern day.

Few questions:

1. Are zombies after you and 10-40 is the only oil availible after you already drained your oil and you need to get away as soon as possible, regardless of possible engine damage?

2. Can you afford $25 of the right oil and want your car to last an extra 10,000 miles in the long run?

That's quite a change for them recommend spec, and a heavier oil. Means it doesn't flow as freely around the engine as it's supposed to.

If you haven't opened it, you can probably return it and get the correct grade?

NO, NO and NO. You have variable valve timing, it only works correctly with the right oil viscosity. Why would you put heavy thick oil in a precision engine like the Honda Fit.

A lot of times the lighter weight oil is used by the manufacturer to reduce the drag on the engine components to ease the amount of emissions.

It will be fine. The 5w is thinner at cold temperatures making turning over and starting easier, but hardly any difference.

Depends on where you live
5W-20 is a thinner oil suitable for cold climate areas
10W-40 is a thicker oil suitable for hot climate
areas like Arizona

If you live in a cold weather area then for sure no. If you live in a hot area it will work, and work effectively. If you live somewhere in the middle i would return it for the correct stuff.

I've used 10W-40 in cars before and it doesn't hurt. As already mentioned, 10W-40 is thicker than 5W-20, so the only way you'd really notice a difference is if you are living in an area of extreme, elongated coldness (single digits F) that would cause the oil to lose it's elasticity. This would cause your motor to have to work harder but even then it would eventually warm up and work fine.

I assume you (1) have never read the manual or (2) got a discount on 10W-40 because hardly any new vehicles use it. Or both. Neither speaks well of you.

LOL ELLIE

If your light switch or door handle goes on the fritz, some service guy will blame the wrong oil so it's best to do what the Owner's Manual recommends. I'll take the leap and suggest you use synthetic.

Gas mileage will suffer. Honda and many others went to 520 for mpg. Stick with it.