oil weight

[CandyRedDHS]

the car says to put 5-30 and my car said low oil so i put in 2 bottles castrol gtx 5-30 and my mechanic told me not to use 5-30 but instead 10-40(not sure though if that is the right weight he told me) he said putting in 5-30 is like running water..what i want to know is will changing it that thick be a problem and me putting in 5-30 again be bad for NorthStar?

[GreenMachine]

2000 and up northstars are actually speced for 5w-30 so unless you have a problem stick with that or 10w-30, both of which the manual recommends for varying temperatures.

[JimHare]

Originally Posted by CandyRedDHS

... and my mechanic told me not to use 5-30 but instead 10-40 (not sure though if that is the right weight he told me) he said putting in 5-30 is like running water..

Lord save us from mechanics who know more than the design engineers. I respect knowledge wherever it may be, but how many mechanics out there have mis-diagnosed, mis-repaired, and mis-allocated blame because they think that because they've torn down a 350 Chevy or a Ford I4 or a Honda, they know everything about engines...

We think nothing of following directions on our microwaves, washing machines, VCRs, etc etc etc but when it comes to an automobile costing a thousand times as much money, we're so quick to follow the advice of someone who knows nothing about it....

[Ranger]

Three of the four cars in my stable call for 5W30, but I stick with 10W30. When I once asked our old Guru if it was OK, he eluded to the fact that GM was forced to go to 5W30 to satisfy CAFE and said that 10W30 was fine. Gave me the impression that GM would not have gone to 5W30 by choice. That is not to say that 5W30 is bad. Make your own judgment. That said, I would not use 10W40.

[submariner409]

Curiously, we used to think of 10W-40 as "water". The 5W-XX oils are used to gain quicker cold start (less than 100 deg. oil temp.) lubrication and still provide protection for a modern engine up to around 100+ deg. air temperature. Ford and Hounda have gone to 5W-20 in their vehicles, including light trucks, and still honor warranty. FYI, 10W- and 15W-40 oils are now OK for use in CC rated diesel engine service (check the rating label). I believe Mercedes uses a 5W-40 "Euro" oil. Go with the owner's manual. Leave the hype for the snake oil merchants.

[HITMONEY]

Just a lil FYI...

The "W" in say 10w-40 does not stand for weight. It stands for winter. The number is the viscosity rating. So 10w-40 would have a 10 viscosity rating in the cold and a 40 in warmer temps.

[codewize]

You're mechanic is an *******.

Read the manual to him. Newer engines like the N* don't require the thicker oils like the old days. 5W-30 it the recommended weight for the N* and many other new engines. Find a new mechanic and don't put anything higher than 10W-30 in the N*

[acklac7]

Originally Posted by JimHare

We think nothing of following directions on our microwaves, washing machines, VCRs, etc etc etc but when it comes to an automobile costing a thousand times as much money, we're so quick to follow the advice of someone who knows nothing about it....

LOL, how right you are, classic quote

[ewill3rd]

Use what the manufacturer recommends in the manual.
Tell your mechanic thanks for the advice and remember that next time he gives you more "advice".

Most owners manuals have a chart that shows temperature and viscosity recommendations. Here is the one for your vehicle, please note if you live in a warm climate area you might use 10W-30 (if the temps never get below zero) but not 10W-40.

On newer vehicles this shows specifically not to use 10W-40.

[clarkz71]

Originally Posted by ewill3rd

On newer vehicles this shows specifically not to use 10W-40.

Or 20W-50