Went to pick up some oil last night and all I saw were boxes and boxes of 10w30. There were only 2 boxes of 5w30 avail, so I grabbed one. What's the difference between the two? Aren't 5w + 10w just the temperatures they can work well in?

 

the 10w is thicker and the 5w is thinner...

Most shops use 10w30 during the colder weather and 5w30 during warmer seasons.

 

Wouldn't you want thinner oil in the winter? Since it's so cold out, it'd be pretty hard to crank if the engine was filled with thick oil.

 

i don't exactly know why they use the thicker one...but thats what they do

 

Although 10W-30 is a good all-purpose oil (and the most common type), Honda is one of the few manfucaturers that specifically designs their engines for 5w-30 and 5w-20. You're correct in the assumption that thinner oil would be better in the winter, Honda's are different.

 

The number with the w is oil's consistancy when cold, and the number after the dash is when it is hot. So 5w-30 will circulate faster when it is very cold out, but will exhibit the same molecular structure as 10w-30 when engine is at running temp. For most intents and purposes, there isn't a great difference. Unless you like to stomp on the gas as soon as you turn the key when the engine is completely dry. In which case, VTEC won't help you anyway (won't engage untill engine is at full running temp). I use 10w-30 Castrol Syntec. I prefer the peace of mind of a little thicker oil when cold, and I always wait till full running temp before I rev over 3000 rpm.

 

my accord recommends me to put in 5w-20 all the time. Ive been doing that since day one and it is perfectly fine and runs smooth. I always use castrol gtx 5w-20.

 

I dont know what shops you use, but thats completely backwards.

If you are going to change weights, go with a thinnner oil in the winter and thicker in the summer. Personally I run 0w-30 synthetic in the winter and 5w-30 synthetic in the summer.

I would NEVER run 10w oil in any of my cars in the winter. Check your owners manual and see for yourself what oil weights are recommended based on the year round temps in your area.
My aunt had 10w oil put in her civic by accident during her last oil change. With the cold temps in the NE, the valvetrain clatter when the engine was first turned over was unbelieveable. It sounded like the engine was starving for oil til it warmed up. I took the car back and had it changed to 5w right away and you could tell the oil was getting to where it needed to be much faster.

The newer Hondas recommend 5w-20 in order to boost their fleet mpg stats a tiny bit, but Im sticking with the xw-30.

 

ive been runnin 20w 50 ever since i got the car. i was reccomended this cause its a high mileage car. is this "right?" btw car runs great.

 

I think if you run thinner oil you'll save gas, Dont know if its true.