I use castrol syntec 5w-30 in my 99 f-150 5.4 does anyone else use this brand? I also mix 1 quart of Lucas oil in there this shouldnt hurt anything should it ?

 

Royal Purple 5w20 is what I use.

 

do you add any lucas oil in there with it ?

 

Royal Purple for me as well....along with K&N oil filters

 

Ditch the Lucas, adds too much viscosity. I use Amsoil 0w30, Royal Purple
5w20, sometimes Redline 5w20. Amsoil oil filters, Napa Gold, Wix, MC, or Mobil or K&N, the latter 2 made by same company and virtually identical inside, so not worth the extra $1.50 for the K&N. I just found a few on sale.

I have a police officer friend that uses Castrol Syntec and he's happy with it. Changes oil filter every 4K miles and oil every 8K.

 

What is worng with motorcraft?

 

nothing. It just doesn't provide that warm fuzzy feeling inside.

 

i dont lol, i use mobil 1

 

Amsoil

 

I change my oil and filter every 4,000 miles because I tow alot and the oil needs to be changed by then.

 

Blue i will be towing 4000 lb will it be ok to tow in OD?

 

I wouldn't recommend it. But thats just me personally. I only tow an empty utility trailer or open car trailer in overdrive.

 

Motorcraft 5w20 and FL820S filter...3k mile intervals (lots of short trip driving, as in, less than 5 miles at a time).

 

Which Lucas do you add with that synthetic oil. The regular lucas or the synthetic kind?. If you use the regular lucas with synthetic it could cause problems

 

Does for me.