I'm a Powerstroke driver myself (1996 7.3l) and I can't help but ask what it was that made you switch to Ford after the Duramax gave you such good service?
Another long time PSD owner here wondering the same thing.
I'll add that Valvoline Premium Blue will give excellent results as well.
Just make sure for warranty that you use an oil from Ford's blessed list, and keep the receipts.
Don't give them any chances to deny anything.
The Duramax exceeded my expectations as far as Durability,breakdowns, maintenance cost,and fuel mileage .Outside of regular maintenance the intake heater fried at 80,000 miles which I had replaced at the stealership and if I would have known at the time I would have just deleted it,and also at 146,000 miles the DEF tank heater took a [censored] and I just deleted it for a couple hundred more than the cost of tank replacement.The truck had a 40hp tow tune from 146k to 250k and then I dropped it to stock power.
Oil changes were done at 8k-9k with Rotella,Delo,Delvac,and later Phillips 66 fleet supreme.Fuel filters at 25-35,000 miles with ACDELCO fuel filters and a couple of times I used the Baldwin equivalent which I did not like because they plugged up much faster and one even left me on the side of the road, and also because the center gasket would stay attached to the filter head assembly on removal,made in China go figure.As far as the Allison I would change fluid and filter at 46k with Dexron VI.
As why I went to Ford it all came down to price.My first choice was the L5P Duramax but the lowest priced work truck with an enclosed bed not a flat bed was $55k.The XLT Super Duty with SXT package was $48900 with all the rebates Ford was having, and my very last option,like way down at the very bottom of the list was the RAM which was the same price as the SD so it was a no brainer.
Huh.
http://www.laurabuickgmc.com/VehicleDeta...e-IL/3054276043
I should have been more specific.Crew cab,long bed,DRW not SRW for hauling the weight I haul.