What oil do you use and how many miles do you have
 

Valvoline has a program where if you use their oil and do the proper oil changes ,they guarantee your engine . What brand oil do you use, and is snythetic ok for high mile engines. Im always afraid after hearing the myth that seals will leak on older engines using snythetic.

Mobil 1 5w/30 Full Synthetic, (132k daily driven miles).

Neglected engines are the ones that usually leak when synthetic oil is used.

Mobil 1 5w-30 full Syn. 152,000 miles.

Mobil 1 5w-30, change it every 5000, on my 85.

I highly doubt any engine failures have ever been attributed to any specific brand of oil.
It really does not matter what brand you use, as any of the major players in the field will protect your engine just as good as the next.

Proper maintenance and how you use the engine play a much bigger roll than what brand of oil you use.

Started with Mobil 1 in my 86 at 118K, ran that motor up to 170K.

Mobile 1, Amsoil or Schaeffer's is what I use depending on where I am and what I can get my hands on at the time of the oil change. I have switched oils and not gotten any leaks. I think it is just a myth

:iagree:
As for the synthetic leaking myth or not, If your seals and gaskets are in good shape, the synthetic should be fine. If your seals and gaskets are getting older and borderline, the synthetic will find smaller gaps than dino oil to leak from.

I have switched to synthetic on several cars with no problems, but on my '88 when I switched at 110k, it started leaking a lot. I had never noticed it leaking with dino oil, but with synthetic it leaked. It was so bad at the valve covers that it would run down and smoke on the exhaust. I replaced the valve cover gaskets and that took care of most of it, but it wasn't done leaking until the next dino oil change.

Mobile 1, 5000 mile brand.

Same here, change every 3,000 give or take.

On my Powerstroke truck, I stretch the interval to 5000 with the better oil. Tried to make 7500 but the analysis showed it was worn out. If it were me wanting to stretch out the oil change interval, I'd certainly get an analysis to confirm how far out it can be done instead of trial and error.

Mobil 1 10W30

Betty Boop: 139,000 Hardcore Miles

The Ghost: 50,000 Extreme Hardcore Miles

Penzzoil platinum 5W30 change every year with new filter before winter storage regardless of miles but usually 1 to 1.5K miles...Some of them a 1/4 at the time:thumbs:

You'r supposed to change your oil?

Brad-Penn High Performance 10W-40

http://www.penngrade1.com/Products/H...SAE-10W40.aspx

I have less than 5,000 miles on a new 383

Mobil 1 synthetic 10w40.

No leaks other than the oil pressure sensor ( common ) needs to be changed ( leaking oil ).

On daily driver used mobil 1 synthetic 10w30 i put 50,000 miles on that engine with same type of oil, no leaks, improved average mpg by 1-3 miles per gallon depending on actual use, engine valve train was spotless ( no sludge build up ), changed it every 3000 miles; sometimes every 6000 miles depending.

Royal Purple Synthetic 5W30, changed every April before the season regardless of mileage.

Mobil 1 5W30 + Mobil 1 Filter - 1994 with 69,000. Change oil & filter once a year in the late fall just B4 it is put away. No Mods - All stock. Drive it like I stole it all summer.

for a long time it was Mobile-1 5/30 winter......10/40 summer or 15/50 in AZ.

When the funds are low, I'll use the walmart brand, Super-Tech synthetic $20 for the 5qt bottle. Go ahead,Laugh ! :yesnod:

it could come from KFC, as long as its synthetic its worth using. Where would KFC get synthetic oil? From rubber chickens I suppose..:rofl:

This engine has close to 200,000 and does not burn any. No real leaks either. It gets changed every 3000 miles during rough service, stretched to 5000 during lite service in winter. Prolong additive at most changes...(when its available)

Mobil 1 "high mileage" Changed once a year before hibernation.