talk all you guys want... but the cap has the right weight printed on it... i believe just to settle arguments like this... 5w30... and thats what i put in all year round... MAYBE if it really hot... i'll put in 10w30 mobil 1 synthetic... whats this 20w50/40 stuff i been seeing?... hold on to the empty containers so you can save some when it blows up all over the road...

 

A few posts up someone mentioned the K&N oil filter. I use the long version of it myself, it's HP3002.

As to 5w30 vs 10w30, yes you could use 5w30 all year round, however 5w30 will thin out quicker than 10w30 (especially conventional 5w30) so keep that in mind. If you compare the specs on 5w30 and 10w30 oils you'll typically see better specs with the 10w30 (lower noack evaporation numbers, higher flash point, lower volatility, etc.) 10w30 uses less (or in some cases no) viscosity index improvers. When these break down they become useless sludge molecules.

 

What's wrong with thinner oil

 

Every engine has a specific viscosity that works best for it, and if you run too thick or too thin you'll have increased engine wear. The LT1 has larger clearances than most engines out there, so it would not work well with a 5w20 oil for instance. But in many cases, 5w30 will thin out to a 20wt oil, I've seen it happen in f-bodies even with Mobil 1 5w30!

These engines like something a little bit thicker than a low 30wt, I believe that they show better wear numbers with a thick 30 to thin 40 weight oil, or an oil in the range of about 12-13cst at 100c.

An engine's viscosity requirement also changes as it ages too, so higher mileage engines need to step up the viscosity ever so slightly (not to a 20w50 necessarily though) So for example if you got good wear numbers with a 10w30 that was around 11cst at 100c when new, you might find at 70 or 80k you'll now need an oil 1 or 2 cst thicker.

 

Make sense. Good Info!
I always been using 10W-30. I knew I would be comming to ICE Box (Canada), from Dallas, TX. So I put the 5W-30 (Syn). I think I am gonna go back to 10W-30 again

 

With the brutal cold winter we've been having here, I wish I had gone with 5w30, although I haven't had trouble starting with the 10w30 Schaeffer blend I'm running. Next winter I'll definitely go 5w30 though, just for an extra margin of safety. I will only run 5w30 from November to March though.