I've decided... I will use M1 10w30 in my new Silverado

Messages
43
Location
Denver, Colorado
After pondering long and hard, after reading the oil analysis forum, after talking to Chevrolet service departments, I changed out my engine oil to Mobil1, but not 5w30,... I used 10w30. I was concerned after putting the 5w30 in my wife's carthat that weight was too thin, and I still believe it is. But a co-worker took me for a ride in his new Suburban that has the same 5.3L engine, and it runs so smoooth. My wife's cars' engine actually ran a little rougher with the 5w30, and the 5w30's consistence was like water when the motor got hot. WE checked my buddies 5.3L engine with the 10w30 M1 when it got hot, and the oil on the dipstick was a healthy consistence(to my untrained eyes). So with 500miles on the new truck, I swapped it out with Mobil1 10w30. I hope I did the right thing! Cheers! [Happy] SoftPoint
 
Messages
3,542
Location
Colorado
It has been a good oil for me in my 5.3. I think it will serve you well. I decided to use the 10w30 year round in Colorado. We will see this winter how it does.
 
Messages
658
Location
EU
Is this another post intended to "shake things up", as you claimed you did before? Those two oils will be indistinguishable as hot liquids. They have the same viscosity at operating temperature: 10.0. Except at very, very low temperatures, you couldn't tell them apart as liquids, either. It's a good oil. Use it in either or both of your vehicles. But your contention that the 10w was not as thin as the 5w when hot is just balderdash. They are both 30 weights, and in this case, with equivalent VIs.
 

SoftPoint

Thread starter
Messages
43
Location
Denver, Colorado
No shaking things up here. I only express my humble opinion on the 5w30 being a thinner oil based upon what I see on the dipstick of the vehicles. I just "appeared" to me that the 5w30 is a thinner oil. I know the numbers published by Mobil are identical. I wonder if there is someone on this site that has the technical knowledge of the product that can confirm or deny this. I also based my choice, from the info on the UOA site. It showed that most of the UOA's on M1 5w30 showed the Kinematic vicosity thinned out after use, but again this is based on the evidence that I have seen, and I formed my opinion thereafter. Now I've ordered a UOA kit from blacstone, we'll see what the real facts are after 5,000 miles. Cheers! [Cheers!] ~SoftPoint
 
Messages
658
Location
EU
No mystery, no technical mastery required. Just check the numbers. And check this out, too. You'll see that that 5w has tested even a tad thicker than the 10w. Can't trust the eyeballs with motor oil.
 

SoftPoint

Thread starter
Messages
43
Location
Denver, Colorado
I think there is some mastery as to how to understand the numbers. The site you have mentionioed is for a VOA. That's all well and good, but I believe a UOA gives you more info on how an oil performs. Just because an oil starts out thicker, doesn't mean it stays thicker during use. Visc. Imprvrs. may give a(for the lack of a better word) false readings in a VOA. Once these Imprvrs have been depleted, the oil becomes a thinner liquid. So the question is, how long do these imprvrs do there job, and what is the effect of wear on them. All of the UOA's show that 10w30 M1 remained a more consistent oil, where as the 5w30 thinned out more. Typically the base oil is either a 5w or a 10w and the Visc. Imprvrs. help maintain the higher number(30). The 5w30 contains more imprvrs, therefore has a lot more to lose in viscosity over time. Just my humble opinion. [Cheers!] ~SoftPoint
 
Messages
10
Location
Paris,Texas
I agree with your Mobil 1 choice. I have used it for years in my 97 5.7, and I have 74,000 and still running the same as day one. I do not understand the statement that the 5w is thicker than the 10w. If 5w is a tad bit thicker than 10w , how much thicker is it than 20w????? Have much fun with your oil changes!
 
Messages
767
Location
Houston, TX
I'm planning on giving my father some M1 (after an Auto-Rx cleaning) for his Silverado with 50,000 miles or so on it. He bought a used 2001 a few months ago and has been running Napa (Valvoline) 5W-30 in it. I'm switching him to 10W-30 Mobil 1 in hopes of getting him to convert to the dark side. He is a firm believer in 'oil is oil' and 'ATF works just as well as an engine flush'.
 
Messages
901
Location
Northern Illinois
"All of the UOA's show that 10w30 M1 remained a more consistent oil, where as the 5w30 thinned out more." Certainly not true in the case of my 02 Silverado 4.3 where the oil is consistently 40 wt at 100C after 6K+ miles, as reported in UOA section.
 

Al

Messages
19,199
Location
Elizabethtown, Pa
Well the latest product information I see for Mobil is: 5W-30 56 cSt. (@40C) 10 cSt (@100C) 10W-30 62 cSt. (@40C) 10 cSt (@100C) So the 5W is thinner below 100C. I suppose if they use any Polymer the 5W will be slightly thicker above 100C [I dont know]
 
Messages
10
Location
Paris,Texas
Softpoint, Do you plan using your truck to tow? Have you included this point in your conclusion to use Mobil 1 10W-30? Did your GM come with an external oil cooler? if so, what volume is it and what flow restrictions will you have with the 10w-30 VS 5w-30?
 

SoftPoint

Thread starter
Messages
43
Location
Denver, Colorado
Yes, I do tow a 1500lb pop-up tent trailer. Although this is a relatively light trailer, I tow it up the Rocky Mtn. passes, which puts a tremendous load on the engine. But I will be towing it infrequently. One thing to take into consideration: I live 3 miles from work, and most of my driving will be this, short trip, stop & go. So how does that make you feel about my choice? And no, I have no external oil cooler. [Cheers!] ~SoftPoint
 
The oil cooler will not cause any inherent loss of flow. I do not see the validity of the towing comment as to determine which lubricant to use. Your normal driving habits should be the "fact in case" of which direction you are to proceed with. I belive that your Mobil 1 10W-30 choice will keep your engine duration at it's peak. The following is why I back these statements: The synthesizing of PAO starts with ethylene gas, a simple two-carbon molecule, and builds till it gets 10-carbon molecules, then combines three of those to form PAO. The result is a fluid more stable than the usual base oils derived from crude. It keeps flowing at low temperatures. It's more resistant to boiling off, and more resistant to oxidation, which causes thickening with prolonged exposure to high temperatures. " [Patriot] This is Mobil 1"
 
Messages
10
Location
Paris,Texas
Over my head Guido! Softpoint, are you sure! Most GM vehicles come with that cooler,it is located on the bottomside of the radiator? This is included in towing packages and HD suspension models due to the increased vehicle weight
 

SoftPoint

Thread starter
Messages
43
Location
Denver, Colorado
I also believe that the 10w30 M1 is more solidly in-grade that the 5w30. Is there an equation that can determine oil life based on its' loss of viscosity over time?(Instead of doing an oil analisys?) This is where I believe the 10w30 will shine. [Cheers!] ~SoftPoint
 

Patman

Staff member
Messages
21,989
Location
Oakville, Ontario
quote:
I also believe that the 10w30 M1 is more solidly in-grade that the 5w30.
This used to the be the case with the TriSynthetic formula, the 5w30 would often thin out to a 5w20 in less than 5k, however with SuperSyn this is no longer a problem. If you look in our UOA section at all the 5w30 SuperSyn results, you'll see that it's extremely rare that it thins out to a 5w20. If it does, it's usually fuel dilution. I still wish M1 was a bit thicker though. Instead of being 10cst at 100c, it should be at least 11 cst. I feel this would reduce engine wear in many applications without harming fuel economy by a significant amount.
 

Patman

Staff member
Messages
21,989
Location
Oakville, Ontario
quote:
Honestly, I would bet that the Mobil 1 10w30 will flow better in the cold than a conventional 5w30.
In order for that dino 5w30 to get the 5w rating, it obviously has a better cold cranking spec than Mobil 1 10w30. Maybe the 10w30 Mobil 1 would show better flow characteristics at considerably lower temps than what the cold cranking spec is taken at though.
 

Al

Messages
19,199
Location
Elizabethtown, Pa
quote:
Originally posted by Patman:
quote:
Honestly, I would bet that the Mobil 1 10w30 will flow better in the cold than a conventional 5w30.
In order for that dino 5w30 to get the 5w rating, it obviously has a better cold cranking spec than Mobil 1 10w30. Maybe the 10w30 Mobil 1 would show better flow characteristics at considerably lower temps than what the cold cranking spec is taken at though.

I think thats exactly right. I have used the Mobil 1 down to -17 F. Not saying that 5W-30 Mobil 1 wouldn't have a better choice-It probably would have been. But the 10W Mobil 1 started really good at that temp. (-17F)
 
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