Conventional or full synthetic

[Black02Silverado]

12 hours ago, Bones454 said:

Is it good to go synthetic with the first oil change?

Don't you need to make sure things seat before putting synthetic oil in until it has so many miles-on it.

In 1995 I bought the wife the bad impala SS LT1 for a family car and ask my mechanic(RIP) about synthetic oil. He told me wait to it gets more miles on it so everything seats its that slick.

He also said synthetic is so slick if there’s a pin hole it will find it and leak he didn’t use it.

At 25,000 miles I put mobile synthetic Oil in and after a month the oil pan started leaking some. To this day I wonder if he was just lucky or that good of a mechanic.

I have a 100 miles on my truck so I’ll keep researching, I drive 8 miles to work.

 

With a ten qt sump and you only driving 8 miles to work. The oil isn't any where near up to temp.  Hopefully you take it out on the interstate once a week to get it all warmed up and put a few miles on it. 

 

From what I have read and experienced short miles is the hardest on oil no matter what brand you put in there.  I'm not one for short oil changes but if you don't do more than 8 miles to work and 8 miles back and don't put much more on it over time, no more than 3 to 5k miles an oil change would be wise.  If in doubt take a sample and send it off to get analyzed. 

[2500W/T]

I am retired military and I used to do the Oil Analysis Program.  Never, ever, seen a vehicle with a bad oil sample, the ones that failed were pretty obvious to detect.  On our aircrafts, saw a handful that came with high iron content, changed the oil to see if the condition comes back, some did, some not.  Those engines/gearboxes used MIL 23699 Synthetic oil, that oil can used in cars, good stuff, the caveat is, the equipment has to have Neoprene Rubber seals, any other type, will dry-rot and leak.  Perhaps early days of the Synthetic Oils was meant to be used with Neoprene rubber type seals and newer vehicles have Neoprene Rubber and/or the oil formula is more Natural Rubber friendly.  What I do not know is when that happen.  So far on my 94 Geo Tracker (bought used with 125,000 miles), is not leaking and I believe no Synthetic Lubricant was used on that motor ever.  Also used Mobil 1 Gear Oil in the differentials and is not leaking either.

 

To be honest, never seen an engine of any kind failed because of "X or Y or Z" brand of oil.  When engines fail is simply Abuse or Neglect or Manufacturing Defect, all or a combination of the threes.

Edited May 8, 2020 by 2500W/T

[Bones454]

I do get out on the highways but will go no more than 5000 miles between oil changes. Before the pandemic it could take 45 minutes to go eight miles lol. Was looking around at oil and will probably go with a semi synthetic oil. Know several people that swear by Rotella in their cars and motorcycles, but don’t think they have a semi synthetic. I do hear the knock from the back of the motor but it’s my first diesel so just thought it was normal. Hope this truck last sure was a lot of money.

[Bones454]

Ok just found out t5 is semi synthetic.

[redwngr]

7 minutes ago, Bones454 said:

I do get out on the highways but will go no more than 5000 miles between oil changes. Before the pandemic it could take 45 minutes to go eight miles lol. Was looking around at oil and will probably go with a semi synthetic oil. Know several people that swear by Rotella in their cars and motorcycles, but don’t think they have a semi synthetic. I do hear the knock from the back of the motor but it’s my first diesel so just thought it was normal. Hope this truck last sure was a lot of money.

Rotella T5 and Rotella T5 Ultra are semi-synthetics

T6 is full synthetic

https://rotella.shell.com/en_ca/products/full-synthetic-and-blend-oil.html

 

The is also Rotella conventional

and they have a Rotella version for gasoline engines.

 

 

[2500W/T]

9 hours ago, Bones454 said:

I do hear the knock from the back of the motor but it’s my first diesel so just thought it was normal.

Yes, they are supposed to sound like that way, that is how the Diesel burn, by heat and pressure.   That is when a Gasser is over heated and/or use a lower Octane fuel, the fuel start to burn before the spark ignites it, the shockwave translate into a knock.  The anti Knock Sensor picks that up and advance or ret@rd the ignition timing to get the best from the fuel, that is also why newer cars are more flexible with what fuel you put in them.

 

An old term for a Gasser that will not shut off was called "Dieseling", have anybody seen the movie Vacation with Chevy Chase?  When he brought the Queen Family Truckster to his house, the engine does not turns off and sounds like a Diesel engine?  The good old days of Carburetors and low Octane fuels.

 

 

 

Since when the word "R-E-T-A-R-D" is censored.. that is absurd !!!  What is the opposite of Advance?

Edited May 12, 2020 by 2500W/T

[curver900]

On 3/26/2020 at 1:29 PM, swathdiver said:

Not for long!  These forums are full of posts of folks with AFM problems and the usual common theme on the low mileage ones is that they used the wrong oil, either by weight or not GM approved.

I used dexos oil in my gas 6.2 changed it early and still lost a lifter at 59k cyl 4 afm cylinder.  I contend faulty design

The dealer sold one and with 23 miles on it it did the same thing as mine.  Some poor other person got a brand new lifter and that was on a 2018.  

 

You have to change the oil in a diesel whether conv oil or synthetic  at the recommended interval, there is no extended drain interval in any reading from any manufacturer I  have seen.  

Edited May 15, 2020 by curver900

[2500W/T]

I have AFM/DOD on my G8 6.0 L76 motor, has already over 150K on the clock and run as good as new.  Waiting for the system break as an excuse to do a delete but still runing.  All I use is Mobil 1 5W30 and change the oil per OLM.

Edited May 15, 2020 by 2500W/T

[Mbower2020]

For what it is worth I just spent 75K on a truck I am not going to cheap out on the oil.  I will probably go with Amsoil 15W40 Max duty Synthetic along with outfitting truck with a bypass oil filter system which will help keep the oil cleaner between oil changes.  

[Grumpy Bear]

46 minutes ago, Mbower2020 said:

For what it is worth I just spent 75K on a truck I am not going to cheap out on the oil.  I will probably go with Amsoil 15W40 Max duty Synthetic along with outfitting truck with a bypass oil filter system which will help keep the oil cleaner between oil changes.  

That's $20-K more that I paid for my first house.   30 year mortgage on a house, 6 year payments on a truck. OUCH!! Ya think in 30 years the truck will be worth $225-K? It pays to protect them. Yes? 

Edited May 19, 2020 by Grumpy Bear

[curver900]

1 minute ago, Grumpy Bear said:

That's $20-K more that I paid for my first house.   30 year mortgage on a house, 6 year payments on a truck. OUCH!! Ya think in 30 years the truck will be worth $150-K? It pays to protect them. Yes? 

 

1 minute ago, Grumpy Bear said:

That's $20-K more that I paid for my first house.   30 year mortgage on a house, 6 year payments on a truck. OUCH!! Ya think in 30 years the truck will be worth $150-K? It pays to protect them. Yes? 

an expense... the more you spend the more expensive it is... it will be worthless in 20 years... ouch... no worries though there is no inflation... oh wait...

[2500W/T]

I would not sweat it, as long it meets GM specs it will be ok.  I stay awat from Boutique Oils, Potions, Lotions and Lubricants.  Is just to darn expensive for no much more for protection.

[Charles Ha11]

Man this topic truly bring out 1000 opinions and many of them are correct. To each is own but my preference is Amsoil full diesel synthetic and I also run the remote by-pass filter system, You will find that the Duramax creates a very black sooty oil and having the bypass system really makes a cleaner difference.