I want to start running synthetic in my 2009 GMC truck (5.3 L). Any advice on the best oil for this? It has 29,000 miles on it...

 

I have been using Mobile 1 for a ton of years but, now days there are a ton more options available. I know Castrol Syntec to be a good option, as well. If your racing, Amsoil, Red Line and Royal Purple as well as Mobile 1 are what you will see on the track, primarily. My '03 Vette (which I race) has Mobile 1 in the motor and Amsoil product in the rear end, tranny and brake lines.

 

have you read this guys review of motor oil, its been around a while
http://micapeak.com/info/oiled.html

he does not like lucas oil stabilizer, but lucas stopped the tic in my old 350 engine and it has not come back in 25K as i have continued to put lucas in at every oil change.

He does say synthetic oil has better oil lube properities and i believe he is correct.
would be great for a new engine, do not know about placing it in older almost worn out junk that I have to drive.

 

Oil's, oil, or is it?

Some guys will tell you it's all the same and just put the cheep's thing you can find in and when your truck "starts to use oil", just put in a heavier grade.

Let me think about that, "when it starts to use oil" could that be caused by excessive wear??

I have a 2005 crewcab 5.3 with 3.73 gears and 86k+ miles and it does not USE oil. This truck is used a daily driver and pulling heavy loads, about half of these miles are from towing a 6650lbs travel trailer.

I only use synthetic oil, in the engine and in the rear gears.

While there are several quality synthetic oils Amsoil, mobil-1, Castrol Edge, and have used all three I am currently using Castrol Edge in the engine and Amsoil for the gears.

I find getting my oil changed with Castrol Edge easiest at Wal-mart but you have to watch to make sure they are putting in the right synthetic oil. You will pay a little more for Castrol Edge but I feel it is worth it.

The other thing you will find is that you will get run more miles between oil changes.

I use the computer in the truck that tells you % of oil life at around 5% I will change the oil. Currently I have 6100 miles on my last change and the computer is at 18%.

One more reason why I keep using Castrol Edge is I had conventional oil in my wife's Honda, one of those deals that seemed like a good deal (free car wash with oil change) until this car did not pass CA smog. Are you kidding me only 70k miles new cat, distributor cap, rotor, wires, plugs, oxygen sensors.

Only one thing left to do, off to Wally world for some Castrol Edge. The car passed smog with flying colors.

So I guess about now you got your keys in hand and are on your way to Wally World for some Castrol Edge, One more thing you use 5-30 wt.

have fun

jvp

 

Here's a link to Castrol USA so you can read their spin on their Castrol Edge product

http://www.castrol.com/castrol/secti...tentId=7050795

jvp

 

I say AMSOIL! But I am partial and it is dang good oil!

 

Why use 5-30 wt in a warm climate, I only ask this because I live in Canada and it gets cold here sometimes and in the winter I use 5-30wt.

 

Look in your owners manual, 5-30 wt. is the recommended weight. I live in CA that's Baja Canada to you, and I now have 90k on my 5.3 and I run in all weather conditions from hot CA. deserts to Canadian Rockies Cold.

Just finished another camping trip to Yosemite in the CA. Sierra's with sub-freezing temps, to Pismo beach on the pacific ocean and then out to Yucca Valley in the high desert.

None of these areas were hot at this time of year but is does not matter I have done all of this in all kinds of weather. From Sub-freezing to 120 degrees. One more thing I pull a trailer that weighs 6650 lbs.

5-30 works.

jvp

 

All I will say about synthetic oil is stay away from royal purple. It caused two compressors to blow right after another. Personally I still use conventional oil. There is a reason that they still make it...... because it works. It's been around since the invention of the internal combustion engine.

 

Thats really the first bad thing I have heard about Royal Purple. I been using it for a while and never had problems, not to say your wrong, but I am really looking into Amsoil. Heard lots of good things bout this.