Hi Breadfan and welcome to MM.net.
There isn't a very big difference between 5W20 and 5W30.
Mobil 1 never came in a 5W20 so they made a 0W20 grade,
and it was approved for FORD 5W20 use.
Now the Mobil 1 5W30 is gone because those knuckleheads came out
with these new Synthetic oils that claim to be good for 5,000, 7,500, and 15,000 miles.
I have been using Mobil 0W20 since my Marauder was new, with a K&N HP-2010 oil filter.
I have been very satisfied with my results so far.
My last oil change was with Mobil 1 5W30 and I didn't notice anything different.
The MPG is still the same, the pressure is still the same,
and the engine runs and sounds the same.
I am sending a sample in to Blackstone Labs, so if anything shows up different,
I'll let you know.
What's more important than what you use, is how often you change it.
You can use whatever you like and whatever fits in your budget,
as long as you religiously change it at regular intervals.
This also goes for your Coolant, Transmission Oil, Power Steering Oil, Brake Fluid, and Differential Oil.
They all have a lifespan, and its not 'for the life of the vehicle' as FORD states.
Pete...
2k04 BLACK Mercury Marauder 300A #810 of 3223
DOB 10/31/2003
DOP 1/2/2004
2k19 AGATE FORD Edge ST with Performance Brakes
DOB 12/11/2018
DOP 6/19/2019
Water Wetter, K&N AirCharger/Drycharger, SS Inserts,
SilverStar 9007SU, WeatherTech WeatherFlectors, Steering Wheel Badge,
AutoMeter Gauges (Oil Press, Voltmeter, and Trans Oil Temp),
ASC 840 VSS Sunroof, Kenwood KFC-C6879ie x4, COBRA Fender Badges,
Z&M Rear Control Arms, FORD GT Coil Covers,
Gorilla Lock Lugs all around, Decklid Designs Trunk Lid Liner,
SCT Xcalibrator2 (Innovative Interceptors) w/Lidio's (Alternative Automotive) Marauder 3.55 tuning,
4R75W by Fred Brown's Performance Transmission, tuned to match Lidio's tune,
DG Motorsports Carbon Fiber Radiator Cover, Zack's Badgeless Grille,
Accel 140034-8 Coil Packs, Granatelli Motorsports Coil-On-Plug wires
Even though I walk through the valley of the shadow of rice,
I will fear no turbo for displacement is with me.