Originally Posted by mpgo4th
Originally Posted by Brian553
Lots and lots of options. If you are following a severe service OCI, any synthetic 30 weight should be just fine. Castrol Magnatec and Supertech are an example.
If you are following an extended drain interval, I would pick something at least certed to ACEA A3. Mobil 1 High Mileage 10w-30 is an example.
If the sky is the limit for oil price, I would probably stop myself at something meeting VW 504? Mobil 1 ESP 5w-30 is an example.
You're in Louisiana, so you don't need a
5w-30; I would probably opt for a
10w-30 if the line of oil offers it.
Oh and yes, this question gets asked a lot.
First off, I hope this doesn't come out rude or argumentative. I legitimately want to know what benefits there are to using a 10w30 over a 5w30. It's my understanding that both would act the same a normal operating temp so why worry about the heavier 10 rating at cooler temps? Again I'm asking to understand and learn, not disagree. Thanks.
Benefit of a 10W-30 over a 5W-30:
To explain briefly and in basic terms, a 10W-30 will hold up better over time than a 5W-30, especially in TGDI engines.
Multigrade oils use polymers that are like spaghetti in that, when they heat up, the polymeric molecules stretch out. This has the effect of thickening the oil, which allows it to flow well at lower temps, but also to provide good viscosity and protection at higher temps.
A very basic article on VII:
https://www.machinerylubrication.com/Read/29842/viscosity-index-improvers
The drawback is that these polymers get chopped up over time and miles, especially in higher powered engines. That results in viscosity loss.
The greater the spread between an oil's winter rating and summer rating, the more of these polymer viscosity index improvers (VII) must be used.
Oils that have a narrower spread tend to hold up better over time. They're more stable, with better Noack volatility ratings. A good, stable oil with a good Noack score is always good, especially for turbocharged engines, and helps prevent coking in the turbo.
And, with the OP being in Louisiana, he's not typically going to see temps low enough to make a 5W or 0W oil necessary.
Again, I'd suggest Mobil Delvac 1 5W-40 in that engine. Or, if he really wants to stay with a 30W, I'd go with a thicker 30 like the M1 High Mileage 10W-30, Pennzoil Platinum Euro LX 5W-30, or M1 ESP 5W-30. All of those have HTHS of at least 3.5. So, they'll resist shear and stay in grade in that beast.
It's a premium truck with a high-performance powertrain. It deserves a great oil.