1997FordF150XLT4.6V8

Yeah I wouldn't put a thicker viscosity in it especially with it being winter. Full syn mobil 5w20 with a mc filter is what I will be putting in next oil change and probably until I can put a blower on it then I will be putting real expensive stuff in it. But that's a few years away lol.

Summers22

iTrader: (2)

I run nothing but Motorcraft 5W20 synthetic blend and FL820S Motorcraft filters.

1997FordF150XLT4.6V8

Wouldn't full synthetic get to the areas that need it most better than a blend? I would run motorcraft full synthetic but I have never seen it. I only ever see the blend.

Summers22

iTrader: (2)

Run what you want. I have run Motorcraft brand 5W20 for the last umpteen years, bought a 01 F250 Superduty with 19K on it, sold it with 200K and zero engine issues, ran Motorcraft 5W20 syn-blend, 04 Focus, ran it over 50K with Motorcraft syn-blend, no engine issues, a 96 Ranger, 01 Excursion, etc, all with Motorcraft syn-blend and all with no internal engine issues. I will stay with what has worked best for me over the last 15 years.

thebreba

From what I've seen through out the years, this is very controversial.
With some saying running 5w-30 get's rid of the infamous 3V Triton tick. Where others say it makes it worse. I'm assuming it's just one of those things you would have to try...

I run 5w-20 Royal Purple in my truck. (2009 F-150 5.4) I'm at 152-153k miles right now. And still runs fantastic. I'll be trading it in this spring/Summer for a 2011+ and have no problems with the people at the dealership taking a look at how the truck runs

I'm not saying you should get an expensive oil like royal purple.. I'm sure MotorCraft would be fine as well. I just haven't had any issues with RP.

1997FordF150XLT4.6V8

Yeah I have only run mc blend in all of my trucks. This will be my 3rd f150 and I have had two Rangers and a 2010 Taurus sho all of which I ran mc synthetic blend and never had any problems. I'm a big fan of motorcraft oil. Just gathering people's inputs on their own 5.4s and full synthetic seems to be their go to. I just want my truck to run good an last awhile.

1997FordF150XLT4.6V8

I get why people try the higher viscosity oil but to me it I don't feel it will help and from what I have read can make the problem worse. Because it takes longer for it get where it needs to. I like rp as well but I think an oil like Mobil will do the job too. I think i would start putting an oil like rp in this truck if I had some money and upgrades in the motor and ran the **** out of it. But for a stock everyday motor it's overkill for me at the moment.

thebreba

Agreed. I don't have to much done other then an exhaust, headers, and cold air intake. I'm not running a turbo or supercharger lol but I still just use it purely bcus I haven't had any issues with it. And I have really liked a lot of the tests I've seen done with it.

None the less keep us up to date with your build 👍

Mulestang

Owned multiple Fords that called for 5W20. Used Motorcraft 5W20 synthetic blend with motorcraft filters in them all. Zero oil-related issues. If you choose to go synthetic, you do not need to change it every 3000 miles. That's a waste of money, and you'd be negating one of the biggest advantages of synthetic oil - extended oil life. I change my oil every 5000 miles. Could probably go to 7500, but I'm very comfortable with the 5K interval here in FL. I'm still waiting to see the 5.4 3v that failed because it used Motorcraft 5W20.

Fordfan2006

I've seen one on here that was knocking after new motorcraft phasers and he put 5W-30 in it and it made it stop and bumped the pressure up to around 30 psi instead of like 12 or something like that.