I would change the oil whenever specified by the owner's manual. If using M-1 rather than cheapo OTC conventional stuff, I would assume that 1. You don't need the 3k/mo. stupidity that's advertised and 2. You can stick with the "normal" change interval (rather than "severe") regardless of driving style. But, this is just my thoughts...and the appearance of the oil (or analysis) would dictate otherwise.
Mobil 1 is supposedly good for the maximum interval recommended by the manufacturer, no matter what the driving conditions, which in your case is probably 12 months or 7,500 miles. I would change the oil and filter once a year. Mobil 1 starts out rather dark looking compared to other oils, so it's hard to judge by color.
So basically I change it once a year, or when the oil gets dark?
How dark is too dark?
I found that using a synthetic reduces a lot of weird engine noise on cold starts (in the winter for instance), and I think its because it shoots into the valvetrain on my 4.6 a lot faster than even Pennzoil GRoup II+ 5W-30. I'll use regular oil for my dad's 300 I6 and my 302 V8 because they're durable pushrod engines, but my 4.6 is a new thing to me and I want to keep it in tip top shape.
There are too many variables that alter your change interval. Type of engine, towing, trip length, city or highway, previous maintenance (or abuse), and driving style.
Maybe I'm a worry wort, but I plan on using oil analysis to determine my drain interval.
Since you are doing short trip driving, you are operating in the warmup mode for a significant portion of your drive to work. So I'd use the M1, 0w-30 instead of their 5w-30 - I'm picking nits here, but it will work better.
Short trip driving will contaminate the oil much more quickly, from fuel/moisture and incomplete combustion. This can result in excessive nitration and sludging of the oil, along with rapid degradation.
I'd recommend testing the oil 2-3 times after 5000 miles/6 months to see how much margin you have left in the additive chemistry. I believe 5000 miles/6 months is still Fords maxium recommended oil change interval?
I'd probably change the filter only @ 6 months and topoff the crankcase. The Mobil 1 filters are very well made, so I'd just use one of those. Trying to save a few $$$ a year buying cheap filters is silly to me.
"SS M1 available this thursday the distributor tells me. Time to get the Timken warmed up!!"
We would like to hear of your results a well.
The M1 SuperSyn is more amber and darker, similar to the 15W50, and has a more pungent
"ester" smell to it.
so you can't be 100% positive that its PAO (like tri syn) ???
you can only use the info obtained from the manufacturer?
I don't understand how a new formulation would result in a higher pour point... this would make me really suspicious. Even with newer additives, a new formulation should be better than the old one. I didn't hear anyone complain about the TS formula, so why did they change it in the first place?
The API has put mandates on the amount of phosphorus and zinc put in API certified motor oils and this is why the pour point has dropped a few points in the new SS formula. Mobil 1 is still a fully synthentic group IV and V oil, not a glamorized group III. Trisynthetic was a great oil however the new SS is even better when it comes to wear rates. You lose a few points here to gain a few points somewhere else. You cant have it all.
I use Mobil 1 10w30 in my 99 Chevy S-10 w/4.3 and change it every 6,000 miles which ends up being about 10-11 months time. The oil still looks good, but I can't bring myself to leave it in for more than 6,000.
I think some of the confusion is that M1 labels used to say something like "pours at -54ºF".
Now they say "pumps at -38ºF".
Note the difference between pumps and pours. Anyway, I still have some Tri-Syn SJ rated oil and the label says "pumps at -38ºF".
This is for 15w50 oil.