Your right oh8gt. The ep line is their only real synthetic. And a mod motor needs a 5w-30 at the bare minimum. Since I started dealing with AMSOIL and actually learning about what oil does and how it really works. Fords motors in australia are the same as here but they spec a 5w-30 there. No cafe laws. A 0w-30 or a 0w-40 would offer the best protection due to it's low cold viscosity which gets the oil to parts quicker and mod motors love to rev so a thicker oil wouldn't shear as quickly. Use whatever ya want,canola oil for all I care I do however suggest reading up at bitog. Bob is the oil guy

I was using Quaker State High RPM from the time I first changed the mustangs oil until January of last year when Quaker State for some unknown reason discontinued the product. Now I use Castrol Synthetic. I used Castrol in my other mustangs, nothing wrong with the Castrol product.

Brand names ftw as far as I am concerned. I change mine out at a maximum of 1500 k's so I figure I'm covered.

No offense but you're wasting your money. Even standard grade dino oil will offer OEM certified protection very well for up to 5000 kms.

^^^I figure at the one year point it's getting a tad old and 10.00 per month is not to bad an expense for oil.

Joe gibbs oil has a lot of zinc . I spent 3 hours at a Gibbs oil seminar hosted buy a fellow that has credentials and certifation that only a hand full of people on the globe have.
People tend to think that the main reason for a high zinc oil is for a flat tappet.Think about this ,every time a piston goes up and down one time it stops 2 times.
Also high lift cams and higher valve spring rates are putting a lot of strain on the valve train.Joe Gibbs did not invent this oil,It was initialy a special blend created for them.They were almost hand cuffed into taking on the product line or else have it go to another race team. Before they got there new oil they were losing 2 out of 10 cams on the break in dyno due to oil failure. Now they only lose 1 per 50. as well as no race engine failure on the track. Gibbs anual team racing budget is 100,million. I am in process of putting in a pro-charged Livernois stroker in my pride and joy 06 Shelby tribute gt.Gibbs for me

Castrol here.

AMSOIL once a yr change when i put it away for the winter. only pit 7-8000km on it a yr.

Castrol syntec here

i use the motomaster (CTC) synthetic oil. i also recently put some ZMax in. any thoughts on that?