dyno 10w40 vs a thinner synthetic blend?

[Tannerm]

Just curious if I would run into any adverse effects at oil change time. She's ran on dino 10w40 for years. It originally called for dino 5w30 but previous owner of 11 years switched to 10w40 years ago. Manual states 5w30, or 10w30 if temp stays above 0*F...

So, my question is this. Is it a safe bet to switch my oil changes over to say, 10w30 full synthetic? Or even 10w30 syn - blend Motorcraft (love that oil.). She's a 162k miles vortec 7400. No oil leaks at this time.

[Lone Star Performance]

I wouldn't due full synthetic because of the mileage and the cleaning agents in synthetic oil. I would stick with what you've been doing, or the 10w-30 Motorcraft blend

[2011GT]

Just run a good dino 5w30. Also switching to synthetic will not harm anything. Only run syn oil if you plan on taking your oil change intervals to 6k plus miles otherwise you're wasting your money. Dino oil will have no problem running 5k plus miles.

[A_A_G]

If it aint broke dont fix it. Why change whats been working for years?

[dangerous_sep]

How about oil pressure do it and report back what it looks like

[Tannerm]

How about oil pressure do it and report back what it looks like

She has high oil pressure. Idle is 40. When at highway speeds, it's around 65-70. Dang good pressure if u ask me.

If it aint broke dont fix it. Why change whats been working for years?

Well I was thinking mpg and that 10w40 seemed a little thick in comparison to the recommended 5w30 and 10w30.

[2011GT]

She has high oil pressure. Idle is 40. When at highway speeds, it's around 65-70. Dang good pressure if u ask me.




Well I was thinking mpg and that 10w40 seemed a little thick in comparison to the recommended 5w30 and 10w30.

Too much oil pressure is a bad thing. 40psi sounds extremly high. My toyota only runs about 10-15psi at idle if I remember correctly.

[Tannerm]

Too much oil pressure is a bad thing. 40psi sounds extremly high. My toyota only runs about 10-15psi at idle if I remember correctly.

I thought is sounded high. But i wasn't sure. I assume this is due in part to the thicker 10w40 oil?

[Super Coupe]

My old 5.9l Dodge truck has had orielly brand oil its entire life. Makes 50-60 pounds of oil pressure when its cold. Around 25 when its warm at idle. It doesn't smoke or leak any oil. Has 228k miles on it. It will use about a quart of oil between oil changes if I pull my race car a lot with it.