scottmach

Seems like a simple concept but many tend to over think this.

SCCAGT

The standard that using 5W20 oil help to achieve is EPA mileage rating numbers. Its thinner oil, creates less drag and less parasitic power loss. 5W30 has worked just fine for years, and as an individual, you will not notice a mileage change between the two weights of oil.
Just as an public FYI, W16 oil is going to be the next oil weight standard that comes out.

JohnnyB15GT

Changing the oil early certainly doesn't hurt, but probably isn't necessary anymore. This came from the OLD DAYS, same place the 3K mi. change interval came from and that certainly isn't necessary anymore.

I've always followed manufacturer's recommendation while on warranty and every 10K after that when using full synthetic (mostly Mobil 1, sometimes Royal Purple). On my 98 Mustang, when I pulled the heads and intake for an upgrade, the cylinder walls still looked brand new. Crosshatching was still clearly visible and no ridge at top of cylinder. This was at 98K+ miles.

Take it for what it's worth, but that's my experience. I'm 64 and have been fooling with cars my whole life, including SCCA racing.

iigneb

Not true at all.... I know a retired exec at GM who used to analyze defects to see if it is worth it or not to have a recall. For Example I had a Trail Blazer SS, anyone who is familiar with this car knows to run 1 extra quart of oil. When he first saw my car he immediately told me to run an extra quart, I knew he wasn't reading the forums to find out this info so how did he know... He knew this because Trailblazer SS's were constantly blowing motors. GM knew the issue. Knew how to Fix the issue. But this information was never made public. Why? because it was cheaper for GM to warranty new engines than have a recall.

This happens all the time in the auto industry for every manufacture in an array of components.. But go ahead and go by the book on your mass produced car

PNYXPRESS

Riiight. Cheaper to replace the complete engine rather than to recall and reprint the service manual, or even just a few pages installed as decals over the pages with the wrong capacity listed.

And this is why GM had to file bankruptcy.

JohnnyB15GT

Yeah, everyone...quick, go out and put another quart of oil in all your vehicles! Before it's too late!

Genxer

The manual mentions changing the oil between 3k and 5k for extreme conditions, not typical driving of course. Upwards to 10k depending on conditions. Personally, I'm not sure how much stock to put in the "intelligent" oil life monitor. I will probably change oil every 5k-6k using full synthetic. Certainly if it goes off before then I will change oil for warranty reasons. My estimated mileage per year will be 10k-12k so that is around 6 months between changes (which is the recommended time interval).

JohnnyB15GT

For what it's worth, I've always used fully synthetic (mostly Mobil 1, but also Royal Purple). Change intervals varied from manufacturer's recommendation while still on factory warranty to 10,000 mi. (or 1 yr.) after warranty period. Never had any issues (over 100,000 mi., current "beater" has 189,000).