My local Rural King now has the Delvac ESP 1 5W-40 synthetic in the 5gal pail for $120 every day. While thats not as cheap as the $100 sale posted above, thats still $24/gal, which is WAY cheaper than the $30 - $34/gal it normally goes for. When you figure in the great Mobil rebates ($60 off a 5gal pail of this oil) it then becomes $60/5gal pail, or $12/gal.... which is what regular Delvac 15W-40 is around here ($12.50/gal on average)
I have been running the regular Delvac 15W-40 for 2 reasons:
1) I have an oil change regiment of changing the oil once a year, around the first of the year. I average 12K - 13K miles/year on my truck. I change the filter (and fill it with a fresh quart of oil) twice a year or approx every 4 months/4K miles. Oil analysis from Blackstone shows the oil to be in great shape for an annual/13K miles oil change. So, since a regular 15W-40 DINO HDEO has no problem going 1 year/13K miles, and we normally dont have much sub zero temps around here warranting the 5W-40 synthetic, and I park in a garage (which helps a LOT, I dont care what people say) and I can plug my truck in if needed.... I didnt see the need to spend the extra on the synthetic, when the DINO oil did what I needed it to do.
2) I get the DINO Delvac 15W-40 for $7.50/gal after rebate at Rural King. Its normally $12.50/gal, and Mobil has $5/gal rebates often on this oil.
My current costs for fuel/oil maintenance for 1 year:
$28.35 - 3.5 gallons Delvac 15W-40 (3gal for full change & 2 quarts makeup/filter change) @ 7.50/each + tax
$18 - 3 Baldwin BT7349 oil filters (changed every 4K miles/4 months)
$24 - 2 Baldwin PF7977 fuel filters (stock bowl location, change every 6 months)
$17.27 - CAT 1R-0750 Filter (Secondary fuel changed once per year)
$87.62 Total ...... I can live with that for fuel/oil maintenance.
Although, if I can get the ESP 1 synthetic for $12/gal, I may have to check into it. My only concern isnt the quality of the oil, but if it is better for my truck than what I am running. The 15W-40 Delvac was designed for trucks like ours. The ESP 1 synthetic was designed for big rigs with long run times, lots of idling, never being shut off etc... Plus, Im not sure if its designed to keep soot in suspension like the 15W-40 DINO. Looks like a call to Mobil to ask a few questions, is in my future lol