I decided to use a dealership in Oakland, CA for a regular service. I read the invoice when I got home when I noticed that they used 5w-30 instead of 5w-20 like the manual says. Will there be engine damage because the oil is thicker? If it's not a big deal I won't make a fuss about it.

 

It honestly won't matter, and with the weather warming up, even less harm.

 

The numbers you are referring to are the viscosity ratings. They indicate how thick an oil is, which kind of relates how well it stays between metal parts and reduces friction. The lower the number, the thinner the oil.

5W-20 is a multi-viscosity oil which is formulated to flow as a 5 weight oil (thin) when cold (the W means winter) but protect against friction as well as a 20 weight oil when hot.

A 5W-30 will have extra additives to raise the oil's protection when hot so it can act as well as a 30 weight oil. You can even buy 5W-40 oil which protects further.

Now you are asking 'Why don't we all run out and buy 5W-40 or even 0W-40 and never worry about it?'

The oil is manipulated to act like a thicker oil. The additive package that makes it act better at high temperatures will wear out sooner than a standard weight oil. What I mean is 5W-40 will not last as long or work as well at high temperatures as a straight 40 weight oil.

The less of a swing in low to high number means the oil isn't 'pushed' as hard trying to be something it's not.

For normal driving I wouldn't worry about using a 5W-30 in place of a 5W-20.

Here's a site I refer to often, you can learn all there is to know about oil:
Putting the Simple Back into Viscosity - Bob is the Oil Guy

 

Well said Goldy Lox, there should be no adverse effects, if it was a super high tolerance high compression sports car motor revving over 7k routinely it would be more sensitive to it but for the Fit its fine.

 

The 5W30 won't hurt your engine. If I had the time I would still raise hell about it, might get a free oil change next time. Beware of this dealer, if they can't get the little things right, I wouldn't trust them with the big things! That's why I always change my own oil. If you want something done right, do it yourself!

 

It's really not THAT big of a deal but it's the dealership, come on. The same thing happened 3 times in a row with my brother's car. He has an '08 Si and it takes different oil than the sohc models.

It just goes to prove that dealership service is in no way superior.

 

Not to worry. You may see a very small decrease in mpg (we're talking less than a couple percent of normal), but otherwise you're fine.

 

Eh, life's too short! Save your energy for the real battles you'll face. Maybe mention it next time if you ever go back. They may have just written the receipt up wrong even.

@mhadden: Why would you think the mileage would go down? Do you have any studies that indicate that may happen? The viscosity at cold temps is the same, so the oil flows as well, it just has more 'stuff' in it to help it perform better at high temps.

 

http://www1.eere.energy.gov/vehicles...r11_fenske.pdf

You will see how thicker oils protect the motor. So basically they trading a few more mpg per tank to a shorter engine life.

 

See additional debate on oil, milage, posting counts, what is an insult and much more in: https://www.fitfreak.net/forums/2nd-...il-thread.html
Coming to computer screens everywhere. [use quick, slightly quieter voice] Not appropriate for all fit members and not sanctioned by the American Psychological Association (of which I am not a members).

 

does this apply for GD3 models as well?

 

The 5w-30 is a thicker oil which means your engine will work harder to pump the oil than it would for 5w-20; your fit will get less mpg tho you may not easily measure that.
There is no difference in additives for either oil. I wrote the specs.
thicker oil wears out no quicker thann thinner oil; the quality of the feedstock counts.
Your biggest concern will be whether they used synthetic or conventional oil. If its not synthetic count on a new filter and oil change in 3-4000 miles. Giood synthetics last 6-7000 miles; do not believe marketeers who try to appear better. ask the engineering department. more often than not the filter doesn't last that 15k either.