Synthetic or dino oil??

rusty01 · May 23, 2012

I have been pondering this question for a while now. First off, my engine has the dreaded "piston slap" upon cold start. Not sure what kind of issue that may be. It goes away after about a min. and I don't drive the truck until the knocking stops. With that said, my 2001 Sierra 5.3 now has just under 107,000 miles on it. Would it be best or recommended to switch to synthetic or just keep running the dino oil? I have been a stickler and changed the oil religously at 3,000 miles on this truck since I have owned it with 63,000 miles on it for the past 4 years. Now I hear of guys going 5,7 even 10,000 miles between oil changes! I plan to tow a lot with this truck this summer (33 ft. 6,000 lbs. TT). What do you think??

AGT · May 23, 2012

Explanation and Anaology;

Let’s talk first about what “dino” oil is (Dino is short for Dinosaur, which is when it started forming). Dino oil is created from something called “Base Stock”. Base stock is refined mineral oil that contains no additives. It is the interim product that is reached after crude oil (that comes from the ground) has undergone refinement. From there, additives are combined with the Base Stock, to create our motor oil. There are 7 main additives which include anti-foaming agents, anti-corrosion, etc, etc. At the molecular level, dino oil contains molecules of varying sizes. Imagine the floor of a gymnasium covered with basketballs, baseballs, volleyballs, and beach balls. Now imagine that all those different size “balls” are moving around, flowing past the floor. Every time a ball surface contacts the floor surface, the ball absorbs heat from the floor. That is how oil removes heat from your engine components, from surface to surface contact.

Now imagine the same gymnasium floor covered in uniformly sized golf balls. Smaller, more uniform molecules can absorb more heat from a surface, because there are more of them AND they have a larger surface to volume ratio which means they have more surface area contact. That’s what synthetic oil is. A man-made “Base Stock”, where all the molecules are the same size, and smaller than those in dino oil. Better heat transfer, better lubricating properties, and a lot wider temperature range without breakdown, are now obtained.

Conventional oils (group II petroleum) and synthetic blends (group II blended with a little group IV) are good for 5,000-7,500 miles. Motorcraft syn/blend, etc...

Cheap synthetics (group III hydrocracked - highly refined petroleum) are good for a 7,500-10,000 mile change interval. Pennzoil, Mobil 1, Castrol, etc...

True synthetics (group IV PAO and V POE) are good for 15,000 or more, depending on the formulation. Red Line, Amsoil, Royal Purple, Mobil 1 EP, etc...

ram1067 · May 23, 2012

I'm using Mobil 1 syn. 0w 30 in my 06 w/65k working fine for me even and a little bump in the MPG.....so ill see if i get 15k before the next oil change...

not going to hold my breath!

MorrisGray · May 23, 2012

I have a 2002 w/ the 5.3L and only 54k miles on it. I am changing to Mobil1 or Valvoline full synthetic this weekend. AdvanceAuto has the Valvoline 5qt jug w/ K&N oil filter for 32.99 ... or ... the Mobil1 w/ Mobil1 oil filter for 32.99.

Very good analysis and explanation AGT.

I have also read and believe that using synthetic oil may help deplete our dependancy on foreign oil...

FuzzyB · May 23, 2012

I had a 2000 Sierra that went just about 200k on conventional oil. So I think you can go the distance if you stay with it. However, I now have an '11 I run Synthetic in...up to you but I say if you continue to maintenance it regularly, it will be just fine with dino if you choose to stay with it.

Babyhauler · May 23, 2012

My 02 5.3 has 198,000 miles. I bought it with 104k and switched to Hi Mileage Mobil 1 shortly after that.

the syn lessens the noise & the time of it. I usually change it about 4000-5000 miles as the noise tends to come back by then and it has consumed most of a quart. My oil change sensor light comes on if I push past 5000 miles. I hate paying the extra cost for it, but I would not switch back. As the example states, you will also gain the heat dispersion benefit when you are towing. Cost is the only drawback, but I run synthetic in everything including my mower & 2 stroke equipment.

Good Luck

Babyhauler

SouthCo · May 23, 2012

The start up noise wont go away with synthetic. But I'd still switch to it for the extra protection. Especially since you plan to tow alot. My 03 Tahoe that I sold with 198,xxx miles was maintained religiously and still had the start up noise too. It ran great and didn't use or drip any oil. I only sold it because my cousin really wanted it and I don't really need 3 trucks. I used mobil 1 in it.

As far as oil change intervals, it's my understanding that the oil can lubricate but it's the detergents that stop being effective. In either case I don't go more than 5k miles. I use synthetic for the extra protection, not to go longer between changes.

burgundyz71 · May 24, 2012

I got my 2010 with 8000 mile on it. I am going to put valvoline synthetic in this weekend due to the amount of towing I do. Not sure what oil is in it now.

jdelrizzle · May 24, 2012

The start up noise wont go away with synthetic. But I'd still switch to it for the extra protection. Especially since you plan to tow alot. My 03 Tahoe that I sold with 198,xxx miles was maintained religiously and still had the start up noise too. It ran great and didn't use or drip any oil. I only sold it because my cousin really wanted it and I don't really need 3 trucks. I used mobil 1 in it.

As far as oil change intervals, it's my understanding that the oil can lubricate but it's the detergents that stop being effective. In either case I don't go more than 5k miles. I use synthetic for the extra protection, not to go longer between changes.

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