Wrong Oil?

[Montana Cruiser]

Got home this evening after braving the lines at Wally World to discover I grabbed Mobil 1 5w-30 (The new 7500 mile blend) and had intended on grabbing 10w-30. Question is, warmer temps will soon be upon us, would you guys suggest I go exchange for the 10w-30 or just use what I have?

On a side note, @ $2.18 a quart, I think I will be running this in the summer and then back to full syn come winter, its a $3.00 per quart difference.

 

[landtank]

depends on how hat it gets out there. In the Owners Manual it has specs. for what temps to run that grade at. Might take a look there.

 

[tarbe]

It doesn't matter. Both oils are the same viscosity at operating temperature. The 5w starts out a little less thick, but of course, even it is too thick at start-up, about 60 Cst at 40 degrees C IIRC, vs 10 cSt at 100 degrees C. The 10w is about 70 cst at 40 degrees C (this is off the top of my head, but you get the picture). Both are thicker than ideal at start-up and 10 cSt at operating temp.

You are fine...no problem.

 

[tarbe]

Found a VOA on both the 5 and 10-30. Mobil has blended these to be a little thicker than the Mobil 1 full synthetic .

The 5w-30 was 11 cSt and the 10w-30 was 10.9 cSt, both at 100 C. Didn't see the 40 C viscosity but that is not what you were concerned about.

FWIW, I run 5w-30 oil of various makes in Houston with good analysis results (between 10.5 and 11.5 cSt).

 

[ryanjl]

I used to use M1 5W-30, but it actually seamed 'thinner' at ambient temperature than the M1 0W-40 I currently use year round.

If I remember right, Cary posted the same thing.

My engine didn't really like the 5W-30 all too well either, as it made more noise and burnt some oil between changes.

 

[tarbe]

I used to use M1 5W-30, but it actually seamed 'thinner' at ambient temperature than the M1 0W-40 I currently use year round.

Your observation is correct. Mobil 1 0W-40 is really a 10W-40 if you go by the test numbers. But unless your average trip is very short and you never spend any time with the engine fully warm, what you were seeing was the difference at operating temp....10 cSt vs 14 - 15.

Marketing geeks Always trying to pull one over on us!

 

[lahar50]

I use 15 w 50 M1 I like it

 

[cary]

Your observation is correct. Mobil 1 0W-40 is really a 10W-40 if you go by the test numbers. But unless your average trip is very short and you never spend any time with the engine fully warm, what you were seeing was the difference at operating temp....10 cSt vs 14 - 15.

Marketing geeks Always trying to pull one over on us!

Really, please explain how the 0w-40 is really a 10w-40. Last I checked it passes the cold pumping test for a 0w, which means it exceeds the cold pumping requriments for a 5w, 10w, 15w, and 20w oil.

To answer the original posters question, as far as hot weather, there is no difference between a 5w-30 and a 10w-30, both are the same thickness at operating temperature. (note this is a simplified explinantion)

 

[tarbe]

Really, please explain how the 0w-40 is really a 10w-40. Last I checked it passes the cold pumping test for a 0w, which means it exceeds the cold pumping requriments for a 5w, 10w, 15w, and 20w oil.

To answer the original posters question, as far as hot weather, there is no difference between a 5w-30 and a 10w-30, both are the same thickness at operating temperature. (note this is a simplified explinantion)

Cary

I was simply comparing viscosity measurements. The pumpability is probably a better comparison.

Oh, and the original posters question had been answered, but I'm glad you agree.

 

[cary]

When looking at the viscosity of oil you have to seperate out the 100c vis from the cold pump test. The second number in an oil, only relates to the 100c vis and the first number only relates to the cold pumping vis.

Cary

 

[wob]

I use 15 w 50 M1 I like it

I just switched to the same, and in the 1000 miles, I haven't lost any oil yet. Before I switched, I was losing about a quart every 1500 miles.