MOTOR OIL ?

Most all engine oil are made from crude.

The difference is in how they are refined and additive packages

Early days of synthetic did have OEM’s not recommend mixing

Today, most say ok and I’d add of the same spec

Issue is with their additive package compatibility and not going to kill an engine instantly. Just altered additive package

As for cheating, sure thing...occasionally local news expose has a complaint and proved via marked oil filter and oil analysis

Do my own, but occasionally use a drive through when squeezed for time and one place just change their rules requiring to stay in the vehicle...so can’t see the oil drain n filter come out

Oasisbob wrote:
After learning a certain oil change facility does not always change the oil filter when doing an oil change I went back to doing it myself.

I've never heard of this. Are you referring to a particular local shop, or is this a chain policy?

I bring along a couple qts of the same oil I use along with me on long trips in case I need to top off for whatever reason..

So far, have not needed to, but it's nothing to take it along anyway..

Mitch

Thanks guys. I knew you would know. This is what makes this forum great. People helping people. In my day mixing synthetic with pertolium was a no no. Things change

deltabravo wrote:

Oasisbob wrote:
My question is if I go synthetic and need to add oil later can I mix petrolium with synthetic?

It's not recommend to mix oil types.

by who?

mix and match, change up if you like. Today's it's an old wives tale, that actually had a basis of fact in the past.

Friend was a mechanic that had a car come in with a failed engine. A little thick sludge came out of the drain. After an investigation, turns out the female owner religiously took her car to the same quickie oil change place for an oil change every 3000 miles... except for (IRC) 50,000 miles, it never got changed.

You can mix synthetic oil with conventional. (See Synthetic Blend oil below).

Blended oil is marketed as Synthetic Blend which is both synthetic and conventional base oils mixed together, but there's no requirement for how much synthetic is used.

High Mileage oils typically have more seal conditioning additives to help prolong the life of the seals. I prefer not to use these oils unless you stick with them for the life of the engine.

Why aren’t you following the vehicle manufacturer’s recommendations?