Mobile1 synethetic is popular for good reason, as fasr as weight, virtually all newer cars call for 5w-30

5W30?  Pep Boys.

I get 5W30 for my car pretty much everywhere.

Here's oil numerology 101, for what it's worth.

The first number in an oil weight (for 5w20 look at the 5) is how the oil flows when it's cold. The lower the number, the better suited it is to colder climates where a car can be hard to start with thick oil.

The second number (20) is how the oil protects when it's hot. Like a 20-weight oil compared to say, a 40-weight in a 10w40.

Later model engines can get away with a lower last number because of tighter clearances, but to me, 20 is pushing the limits of sanity. Only 10-weight is thinner, and that's what you'll pour out of a hydraulic jack. Extremely light!

We gotta' remember that these cars are designed in Detroit, so the numbers you see are usually reflective of that climate...COLD winters! Think about where you live, drichard--San Jose. Believe it or not, our summers in Alabama are routine around 95 degrees and up, only the humidity makes it about 105, so I run a 10w30 year-round, and could probably get away with 10w40, but lighter oil means less drag/more efficiency, so there you have it.

I hope this helps you. By the way, Consumer Reports did a comparison with some NYC taxi cabs a few years ago that put to rest the differences in most oils...as long as it's not a dollar store paraffin bottle of crap, it's pretty much all the same with regard to protection. Only when you plan on going for l-o-n-g intervals in between changes and/or extreme abuse of the oil (I know, I know, that's YOU!), does a synthetic make an appreciable difference.

I was a Castrol nut for years due to some early experiences with air-cooled Beetles (a story for another time and forum), but since I did some research I've gone to 5000 mile changes with house-brand oil (the vast majority of house oil is Exxon or Havoline oil and Consumer Reports sez they're as good as the major names) with a primer bottle of Lucas Oil Stabilizer. That stuff STICKS!!!

Anyway, no damage yet, and close to 200,000 on two different vehicles. The key is REGULARITY of oil changes.

Tin Kicker

PS - Particular brands are most usually recommended due to a pre-negotiated agreement between the manufacturer and the oil company--for each one's mutual profit.

Addition to previous post -- SYNTHETICS ARE ALWAYS GOOD FOR THE SIMPLE REASON THAT THEY DO NOT BREAK DOWN. IN THAT WAY THEY ARE SUPERIOR TO ORGANIC OILS.

My vote on brands here (which CAN matter, due to different scientific approaches to making the oil), is Red Line. I will support that brand til I die. Excellent juice of life!

By the way, Consumer Reports didn't test Red Line, so I can't group it in with the others when I say that they are all the same. Red Line is definately superior.

Tin Kicker

Good posts Tin Kicker

Hi everyone,

TinKicker, thank you for your oil 101. I guess we all have our preferences.

Concerning the climate differences, you are right that a 10w might be fine in non cold region, but I do not see why a 5w would be a problem. Concerning the hot enine protection index, the climate is not relevant anymore. You might wish to protect your engine better with a higher index, but I always feel that if the engineers who designed the car say that 20 is what the engine runs better with, I should go with that... I'm not sure we could see any difference between your 10w30 or my 5w20, but in doubt, I will always go with manufacturer specifications.

To mdvaldosta: 'Preciate the comment!

To drichard: I agree that we probably wouldn't see a difference with those different weights. It's just the fact of knowing what's in there...psychological, you know. Bottom line is, your choice is your freedom, your freedom is your power, your power is your Mustang, therefore your choice must be your Mustang!

I've seen way too many old coots drive jalopies for thirty years with what looked like asphalt for oil in them to think that the technical end of motor oil is deadly important to our sport. On the other hand, you're justified in going with manufacturer specs. I just choose to fly in the face of the whitecoats...I like proving there's ANOTHER way of doing things, if not a BETTER way. That's why I root for the V6ers...I'm contrary as a constipated mule...and almost as good looking.

Peace in all, Tin Kicker

Amen Tin Kicker,

what's important is what makes us and our stangs feel good.