So is there any difference with 505.01 and 507.00 (both 5w-30) in fixed oil service for 1.4TDI (75)?
NO, it does not! Parameter which reflects ability to withstand „acids“ in the oil aka lots of starts is „Total Base Number“ = TBN. Higher the number the better. The thing is that 507.00 is „universal“ oil that service can pour in any VAG car but it has some downsides. First downside, especialy for me, is that it has to be gentle for DPF (same as ACEA C3 oils). That means that some additives (e.g. ZDDP) really good for friction reduction is not present and are substituted with other substances which are not that good. Another downside is that it is not suitable for engine high loads. Upside is better viscosity stability - usualy viscosity of the oil changes during time in engine, usualy it begin to be less viscous. VW507.00 (SAE 0w or 5w-30) are better in that compared to VW505.01 (SAE 5w-40). And this is the case it is suitable for LongLife intervals = long drives, warm engine a few starts...
I suspect the 507.00 just has a different additive formulation to cater for the build of combustion contaminants and acids in the oil over the longer service life.
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