I thought I'd do a cost benefit comparison between these two oils as a number of us are using the 5-20W. I recently did my first oil change at 1700 miles on 2011 SR5 and used 5-20W mobil 1 because it was sold in bulk 5 qt at walmart. I'm now currently at 4400 miles. I've noticed mpg has dropped about .5 miles on the display as well as when I do a calculation based on fill up. Given the present cost of gas I wanted to crunch the numbers and see if I was coming out ahead by using the cheaper 5-20W. Based on a planned 5000 mile change interval the answer is no

Assuming gas at $4 gallon
with most of my driving on the fwy I've averaged 20 mpg



-For every 20 gallons ($80) I'm losing about 10 miles by using the 5-20W
-There would be approximately 23 fillups between oil changes which equates to roughly 230 miles lost.
That is an additional 11.5 gallons of gas at $4 a gallon or $46

Toyota 0-20 is $8.50 X 6.5 =$55.25
vs 5-20W 5 qt at $26 + $6 (1.5qt) = $32

Up front savings with the 5-20W is $23.25 but that will be negated by poorer mpg and you get the peace of mind of knowing that you used the recommended 0-20W intended for the car. Again my driving is mainly highway so you may experience even greater loss of mpg with stop and go.

Any full synthetic will be fine but 0w-20 has a better pour rate and will provide better cold start protection. 80% of engine wear occurs at start-up (regardless of temp). Also the Toyota 0w-20 was specially formulated (exclusive) with a very high moly count and is proving to be very good oil, at a reasonable price.

Koz