[rlarsen462]

Sooooo...are we supposed to be using Dexos1 Gen2 (which is apparently the only kind of Dexos1 currently available) or Dexos2 for the LT4's? Is there a downside to using the Dexos2 anyway, otherwise?

[wakespeak]

Originally Posted by rlarsen462

Sooooo...are we supposed to be using Dexos1 Gen2 (which is apparently the only kind of Dexos1 currently available) or Dexos2 for the LT4's? Is there a downside to using the Dexos2 anyway, otherwise?

Dexos2 has better high temp durability (HTHS of 3.5 or greater) and common in the EU because it also has a diesel rating. My rule of thumb is if your oil temps reach 230F often (most people see max of around 210-220) you need an oil with an HTHS of 3.5+. Most xw-40s have an HTHS starting at 3.5, but very few xw-30s do except those spec'd for European cars (ACEA A3 rated).

The only downside to a Dexos2 oil might be slightly lower fuel economy, but we're talking .5mpg. Otherwise it is just more expensive.