Cadillac Owners Forum banner
5K views 30 replies 14 participants last post by  mtflight 
#1 ·
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?
 
#3 ·
... 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.... :banghead: :banghead: :banghead:
 
#4 ·
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.
 
#5 ·
:bigroll: 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.
 
#7 ·
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*
 
#9 ·
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.
 

Attachments

#15 ·
Not trying to scare you or anything but....
I would recommend changing it before too long.

The chemicals that control the viscosity don't work like "mixing 30 and 40 gives you 35". Mixing oil wieghts gives you something totally unpredictable.
While I don't think it will do any damage, I wouldn't recommend running on a mixed grade fill for any longer than you have to.
 
#21 ·
Curiously, the label on a pint of GM EOS specifically cautions against using it or any other additive in everyday use in GM gasoline engines. It is a breakin lube fortifier for flat tappet engines, primarily. My 5 new pints of EOS will sit on the shelf until I finish 2 Olds 455 marine engines this spring. Any name brand oil, dino or (dino)synthetic in the grade recommended in your owner's manual for your ambient temperatures will keep your engine happy. Modern oils have to keep fanatics like us happy, as well as Granny, who may not check anything for 18 months.
 
#22 ·
They just recently changed the label . It's for the same reason new oils have less ZDDP. They claim it will damage the catalytic converter. EOS stands for Engine Oil Supplement. It's no different then using Rotella or other diesel oil.
 
#23 ·
clarkz71........Yep, true. I think GM is trying to toe the line on gasoline engine emissions, because that seems to be the current news-event buzzword. Now we're seeing the media climb on the ethanol thing. Anything to sell air time to the masses.
 
#28 ·
Caution.

It appears that the new Diesel oil formulations for 07 have less ZDDP.

CI-4 is the Rotella we love while CJ-4 is the new one. It's labeled Rotella T-Triple Protection.

I'm still unclear about the whole situation, but apparently it's all emissions related (the cut in ZDDP). Good thing they still make CI-4.

I'm going to add EOS... it's almost $9 a quart. How much do I add to somewhat level me off to the CI-4 standard.

From now on I think I'll go with the current API, and add EOS... or maybe I'll splurge and continue to use Rotella and add the EOS. Thoughts?
 
#29 ·
From what I understand, all that's needed is 16 oz, (1/2 qt). That's how it's sold anyway.





EOS - Engine Assembly Prelube

Specifically formulated as an engine assembly lubricant. E.O.S. provides outstanding protection against run-in wear and piston scuffing, as well as run-in camshaft lobe and lifter scuffing resulting from insufficient lubrication.
Size:Item #:16 oz.1052367
 
#31 · (Edited)
From what I understand, all that's needed is 16 oz, (1/2 qt). That's how it's sold anyway.

Ok it would not surprise me if I did this wrong.

DATA
E.O.S. has ~6000 PPM of ZDDP
API SM oil (2005) has ~870 PPM
API SH oil (1996) has ~1300 PPM


7(870)+0.5(6000)= 9090 and 9090/7.5= 1212 PPM


So @ 7 qts of API SM, + 0.5 qt E.O.S = 7.5qt @ 1212 PPM

Translation:
Adding 1 pint of E.O.S. to 7 quarts of API SM oil (today's generic motor oil) will get the zinc levels close (1212 PPM) to what they were back in 1996 (1300PPM)

RotellaT 15W40, CF-I (not the newest 2007 CF-J) has 1400PPM
The CF-I Rotella has more ZDDP than 7 quarts standard API SM plus a can of GM E.O.S.


In Other News...

I just picked up a pint of EOS @ $8.79
Funny that the invoice says it is discontinued?!
(or maybe that's not funny because it could be reformulated to have less ZDDP????)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top