My reasons for using a full synthetic engine oil

[metroplex]

1). Preventing excessive piston ring wear
2). prevent valve stem seal "hardening" over time, and basically keep all the seals in good shape
3). Keep rotating parts and internals in tip top shape
4). Prevent the engine from having excessive blowby at a later time (I Hate seeing a high mileage engine with 3" of old oil stuck to the TB and crankcase vent tube)

Are these valid reasons?

If so, would Group III "synthetics" NOT fulfill these reasons? Meaning, are PAO synthetic engine oils the only ones capable of fulfilling these 4 objectives?

 

[TooSlick]

Metroplex,

I have seen good wear rates with some of the 5w-40, Group III "synthetics" (Delo 400, Petro Canada) in the VW TDI diesel engine ....Where I am not sure they stack up to the PAO/Esters is in minimizing high temp engine deposits. Since this technology is fairly new, you don't have a 25-30 year history like you do with Mobil 1 and Amsoil. I also don't think they will hold up as well for extended drain intervals, since they rely more heavily on additives to achieve PAO like performance (pour point depressants and increased levels of anti--oxidants and VI modifiers)

I consider the Group III's and synthetic blends to be "mid tier" products, between conventional petrol oils and the true synthetics. For $2.50-$3.00/quart, I think they are a good value ....anything more than that and I'd use the PAO/Ester product.

TooSlick

 

[metroplex]

HMmm

I'm mainly interested in seal protection...

The front and rear main seals along with the valve stem seals.

Then I want protection for the rings - to keep the engine from just spitting out oil through the PCV system at a later time... There's nothing sadder than an engine that's blowing out oil

If I go the Mobil 1 Route, how often MUST I change the oil in order to keep the engine in tip top shape? I drive a max of 8000 miles a year, mostly city driving (6-8 miles one way).