To me these oil threads are not much use - it is essentially all anecdotal information - I use this, my friend uses that... with no objective evidence to back up any of the benefits that might be realized.

Oil selection depends on more than just the motor. Most notably - driving environment and driving style. Do you live in a hot climate? Do you drive ten minutes to work (operating temps never reached) or an hour each way?

The right oil for your particular application can start with a suggestion, but it should end with a test of your used oil. How do you know this particular oil is better for your motor? Do you get better mpgs? Are there wear metals present in the used oil? How long is your change inverval?

To answer these questions, I use Blackstone oil laboratory. For less than $30, they accept a sample of used oil and report back on what the deal is. In most cases, the ultimate point of this analysis is to be able to extend the interval. Most oils don't break down enough to get rid of them inside a 3000 mile interval. Some guys that have their oil analyized every time are sitting at 10,000 mile oil change intervals with no increase wear on the motor. Having consecutive analysis reports gives you a history of what's coming out of your motor - changes are easy to spot when you have before and after info.

A great site to learn more than you ever wanted to know about oil:

www.bitog.com

Yeah, but what oil are you running?

lol

Touche!

Winter - Mobil 1 5W-30 Extended performance
Summer - Shell Rotella T6

Getting 7K on my winter oil, 8K on summer oil between changes.

I agree with most of what jumborules has said.
We have a 97 dodge ram with over 300,000 on it .We still are only about 1/2 qt low when we do a oil change at 3000-3700 miles
We used valvaline for years and then went to the high mileage valvaline after 250,000 miles. The truck does not smoke and still runs strong
I ran the same thing in our first miata
On the second one I had seen a miata owner doing some test on the rotella and when we went to pick the second 96 up from having a motor put in ,I ask what they used and was told they used the rotella as well
I know a guy that did take the oil from his airplane strained it and then ran it in his cars. it was shell oil and he never had a problem with either of them
Years back I was sold on havoline and then penzoil and then quacker state
Found all of them would start sludgiung up badly.
I never saw the sludging with the valvaline and do not have enough personal knowledge to speak on the rotella
Since the topic was more what did you use than why do you use it I said the rotella

I've done UOAs on Amsoil High Zinc, M1, Valvoline Race, and Foremost and Amsoil did the best. Foremost had more of.the chemicals I care about, less shear, and its cheap.

T6 or mobile1. Whatever is on sale.

What is Foremost?

Big Lots has the QS 5w40 euro spec synthetic for $4 a quart-that's about half price. None left in Western PA-lol

QS is Quaker State?