Hello...This is my first post...
I recently bought a 98 Maxima Se & I would like to know what kinda oil I should run threw it. I use mobil 1 synthic but should I get 10 or 5w-30.

 

 

5w30

 

always use 5w30

 

Why do you say 5w-30? I always use 10w-30.

 

manual says 5w-30...

 

really?? I have 151,000 miles and I use Mobil 1 10w-30. Should I switch back to 5w-30? This kind of stuff worries me. thanks

 

Owners manual says 5w30 or 10w30 are both fine. Don't worry.

 

whats the difference on 5w30 and 10w30? Which one has the most protection to the engine?

 

It's all the EXACT same base stock 30W oil. Straight 30w though would be too thick for a cold-engine startup. So additives are added to "thin" out the oil a bit when cold and extend the viscosity range.

The lower the first number the thinner the oil when cold. So 5w30 would be a little thinner than 10w30 which helps lubricate stuff quicker on startup.

The bigger the stretch from the base stock (i.e. 0w50) the more additive packages and the more likely the oil won't last under extreme use.

The diff between 5 and 10 isn't worth losing any sleep over or even this post...

-RMB

 

If you're in florida I can't see that 5w would be worth it. I'm in Canada, so 5w it is...

 

You won't realize a significant difference between 5W and 10W synthetics until the temperatures get below what you'll see in FL.

 

so why the recomendation to use the 5w-30 in the manual then? They don't expect most owners to be in temps where it makes it necesarry, so why bother to tell us that then?

 

Good question.

In the same vein, I've wondered about all the discussion about manual tranny fluid from Red Line. Most folks go with MT-90 (75W90) whereas I went with MTL (70W80) since I live in Toronto, Canada and was having a tough time finding MT-90 here. I'm still trying to figure out whether the difference between 80 and 90 on the high end makes that much of a difference given where I live.

 

Because at the time that manual was printed the 5w30 was the best viscosity oil for the widest range of temperatures. The "thinner" oil on startup too helps with fuel economy numbers which helps them sell more cars.

That doesn't mean 10w30 wouldn't work just fine in a warmer climate.

-RMB

 

Also keep in mind that the manual is based on conventional oils is not geared towards synthetics at all. You could safely use a synthetic 10W-30 in areas where I wouldn't recommend conventional 10W-30's.

 

in my other car I used 5W in winter since its thinner and 10W in Summer, that car was a 92 sunbird with 275K without any significant problems. Yes its not a MAX, but the same principal should appply

 

Yeah that's what I did in my 3rd gen....but since the manual recomended the 5w I decided to just use it year round. So on the opposite side of the question what am I losing by using the 5w instead of the 10w? Does the 10w provide better protection against engine wear?

 

If we're talking about conventional oils, using a 5W-30 under high temps. in the summer will cause it to break down faster than the 10W-30 would. If we're talking about synthetics, you're not really loosing anything.