Temperature range and recommended viscosity range

[moribundman]

(I hope I'm ALLOWED to post this picture...)
Here is a link, just in case:
http://pictureposter.audiworld.com/50038/oil_chart.jpg

Here is the oil chart for my '96 Audi A4 with the 2.8 12v motor.

As you can see, I can supposedly use these viscosities:

Full Synthetic:
5W-30, 5W-40, 10W-30, 10-40 (I use M1 0W-40)
Works for ambient temps from below -20F to above +95F.


Dino Oil:
5W-50, 10W-50, 10W-60
Work practically for the same temp range as the full synthtics above.

15W-40, 15W-50, 20W-40, 20W-50
Work for ambient temps from -15F to above +95F.

5W-30, 5W-40, 10W-30, 10W-40
Are recommended only for temps under 60F.


Now, we all talk about the fact that engines are designed to use a certain oil thickness, due to clearances. However,looking at the chart Audi provides for my car, I can use pretty much any viscosity, as long as the oil I use is within a certain ambient temperature range. Isn't that just a tad strange?

Opinions, please!

 

[Matt89]

No idea. I gave up on trying to understand viscosity/temp graphs long ago - like how my old Volvo could run fine on 5W30 until the magic temperature of 86F was reached, then 10W30. The engine ran at the same temp all the time so I'm not sure how the ambient temp is relevant (unless you're talking about cold flow).

Anyway, I love the graph they have for my new Honda. Superimposed over the whole temperature range is one single bar labeled "5W-20". Not sure they needed a graph to tell me that!

 

[Jimbo]

First, I'd like to know what dino oil is available in 5W-50 and 10W-60. Castrol offers both only in synthetic here.

Can forum members outside of North America tell us what Honda recommends for current models. I'll bet that 5W-20 is specified only in NA for CAFE reasons. The car companies treat North American customers like morons. We are too stupid to look at a temperature chart. Just tell them one weight, otherwise they, or even the dealer, won't be able to figure it out.

Audi, BMW, Volvo, and the like may go too far in the other extreme with overly complcated viscosity charts.

 

[Kestas]

Jimbo, I can understand your annoyance at the auto manufacturers, but sadly a lot of North American customers ARE morons. Just look around you and talk to any car owner who isn't a "car-guy" as ourselves.... it's pathetic!

One example...... my girlfriend puts 25,000 miles a year on her car. When I tell her it's time to change the oil she says, "Already! Why? You just changed it a month and a half ago."!!!

 

[moribundman]

Ambient temps make a big difference. I used to get an oil light in my Scirocco for a few seconds due to low oil pressure at high ambient temps combined with high speeds after slowing down. That was a 5W-30 oil then. During the colder season, or with a thicker oil I didn't have the problem.

 

[JohnBrowning]

No that is not strange. It is how it is supposed to be. Most Americans have been brainwashed into thinking that they can only run one weight of oil and it had bettter be 5W30 or 5W20!!! This is how all manufactures presented the consumers oil choices before C.A.F.E. showed up on the seens. I will admit that it is rare to see the synthetic or conventional listing and so much over lap. Audi is doing a good job of informing and educateing their consumer!!

 

[moribundman]

It would be even better if I could get a hold of an updated version of that chart.

 

[Dr. T]

That's weird that your manual differentiates between dino and synthetic. They usually don't. That's because this tid-bit doesn't matter when it comes to viscosity. You should use the correct viscosity for the temp. range required regardless of base oil type. That said, it's nice to see you can use just about any oil grade out there!

 

[moribundman]

Well, compare for example the ambient temperature range for 5W-30 synthetic with 5W-30 dino. They are NOTHING alike. That's why I said that chart was strange.

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