Could you please explain the 4T MC part?The supertech 5w40 would need a VOA for better info concerning the meets/exceeds on the bottle label. Anyone using it?
Napa around here has the Valvoline VR1 full synthetic 10w30 ... usually with an inch of dust on the bottles. Still a viable good choice.
Don't forget about OP's location and product availability. Should post a picture of the oil shelf at the local autopart/deptstores. 10w40 synth motorcycle oil might just trump some of the fancy stuff. Castrol/Mobil1 full synthetic 10w40's 4t MC oils are truly great oils for those not hung up on SP/GF6
I wouldn't obsess about Zinc/Phos levels, but the Full-SAPS Euro oils, like this one, are higher:Btw, does anyone know the Zinc rating of the Mobil 1 FS 0W40?
My 1990 Corvette ZR-1 with the Lotus designed LT5 will be going in for some servicing the first of next week, and I won't be able to get my usual Amsoil Z-Rod 10W-30 by then. The LT5 wants its high ZDDP levels, so standard oils in the 800-900 range won't work.
I was looking for the High Mileage Mobil 1 at the local Wal-Mart, and all they had was 0-20 and 5-30.
Being in Canada, some of the smaller brands that can be bought in the US aren't easily available up here.
Any plan B recommendations? Oils that would do lesser harm?
Liqui Moly MoS2 Anti-Friction 10W-40 has been recommended as a viable option, but I'm not that familiar with it. Seems the ZDDP levels are good in it.
There's no maximum for Zinc, it's not defined. As @RDY4WAR has gone into in the past, Zinc is just there to neutralize the Phosphorous. Phosphorous is what started being capped, starting with API SM.Hmmmmm.
But.. what about Zinc? (It appears there is "no maximum" for Phosphorus, like your article states)
Well, that was my point with my first post in this thread. It's an engine that's cam-over-bucket, very much the same as most of the Euro V8's that spec'd a Full-SAPS oil like M1 0w-40 (hence my recommendation). Proof of performance is validated through extensive testing as not only part of A3/B4, but also A40, 229.5, 502 00/505 00 and historically, LL-01 before 0w-40's were no longer being approved for that one.Now, for extra credit.. maybe.... do you think OP is over-thinking the ZDDP part of oil for his LT5 Corvette engine? Or not necessarily. (Sounds like he could have done well with QS Defy, if ZDDP was a thing.)
I've asked myself a ZDDP question in the past, as well, now I'm leaning towards that maybe oil has come past needing ZDDP to protect an engine that may have needed it when it was made.
Well, that was my point with my first post in this thread. It's an engine that's cam-over-bucket, very much the same as most of the Euro V8's that spec'd a Full-SAPS oil like M1 0w-40 (hence my recommendation). Proof of performance is validated through extensive testing as not only part of A3/B4, but also A40, 229.5, 502 00/505 00 and historically, LL-01 before 0w-40's were no longer being approved for that one.
Phosphorous is an important anti-wear component, which is why we see it used so universally. ZDDP also has an LSPI mitigation mechanism to it, so decreasing the levels exasperates LSPI, which is why we saw calcium being reduced (replaced with magnesium) to try and counteract that. That's also why the Euro marques that spec'd Full-SAPS oils weren't having LSPI issues with TGDI.
With the reduction in phosphorous, other compounds were used, some of them organics that don't show up in VOA/UOA's, to make up for the loss of its AW properties.
It seems, the "sweet spot" for phosphorous for AW in a sliding contact/follower arrangement is around 1000-1100ppm, if we consider the Euro lubes that didn't have any restrictions on phosphorous as being our barometer for that. Of course that's part of an overall fully formulated package with other complimentary components in the blend, and has been rigorously tested.