Archion

How is the same weight oil thinner? The weight and viscosity are measured and certified using the same tests. Who ever told you that is an idiot. If it is thinner than they could not legally call it 5w20.

Archion

no, 10w30 is bad, you could use 5w30 as that is really what the engine is designed to use, they just use 5w20 to meet epa fuel regs. 10w30 is too thick for the tolarences and seals. maybe after 100k, but not now.

LAK3RS

So, do yall think that 5w30 would fit this car the best? Or just stick with 5w20...

lugnut

+1


Also the 4.6 engine has variable cam timing which is hydraulically operated for the mechanism to operate correctly you should always use a base 5W this will insure the oil flows as designed and insure you get maximum performance and gas mileage. If you are worried about summer temperatures then use a 5W-30 , 5W-40 or even a 5w-50 this would give you the protection you want. I would recommend you change these higher viscosity weight oils at least every 3-5k since they have more additives and will tend break down sooner then a 5W-20 oil.

07GT

Stick to the 5w20, don't worry about it being too thin, it was designed for it. I've ran thin synthetic oil on 70's style motors, raced the hell out of them, and still no problems. Bearings and cylinder walls checked good. Don't worry, be happy!

Goldenpony

5W20 synthetic is fine in the summer. People that are afraid to use it are thinking in the 60's. The Dinooils of today are orders of magnitude BETTER than they were even 10 years ago. The Synthetics are even better. No worries mate!

BAMFstang

How about just stick with the manufacturers recommended weight of 5w-20.

They engineered the cars and probably know what they are talking about.

Full syn or syn- blend is fine, whichever you choose.

Ford puts a blend in from the factory.

mygt500

Stick with 5w-20 as recommended....change regularly and forget about it!

Ford_Dude

the 5W is the cold weather test cert not the viscosity
the 20 is the viscosity so 5W-30 and 10W-30 are the same weight but with the 5W you can still crank the engine even if its -50F but if its 10W only about -35F
the viscosity is measured at standard air pressure and temp meaning sea-level altitude and about 75F
then for the W test the temp is lowered until it gels upan viscosity reaches a limit that was determined that an engine can still start with

if you don't care the brand of oil you use then you can find 0W-20 and with that you can drive the arctic circle
RP makes 5W-20 and thats what I use in TEXAS

BlackPhantomGT

http://www.bobistheoilguy.com/