I have heard that synthetic oil should never have to be changed because it's synthetic, and that you should only have to change the filter? does this hold any truth? I'm running Castrol Synthetic 5-20 in my pony now, and I change the oil about every 6-7k. How often should you change out synthetic oil? Thanks

Synthetic does break down, just not as fast. I'm still changing mine at 3000 (Mobile 1) but only cause the car is still under 10K miles.

6-7K is fine, and you could go more...Personally I wouldn't, at least not in 'my baby' but on a POS I've gone 20K with no problems.

+1 - while synthetic lasts a lot longer and does not have as much volatile losses as dyno oil, you still need to get the wear particles out. I would also think that combustin gasses effect the life eventually making it less effective.

Well my dad is an engineer at exxon mobil.
here it goes:
Synthetic is man-made whil patroleum oil is from natural crude.
I can really care less if you buy Mobil, and Im not trying to convince you to get it, but I am just gonna give you the facts...

Mobil One is fully synthetic and shows virtually no breakdown within 30 thousand miles.
Thats why Mobil extended is intended to be changed every 15,000 miles. All you have to do is change the oil filter and fill it to maintain oil level.

So I only use mobil one in everything because its pretty darn good.

cheers

It does still break down, just not as quickly...you rfilter however is the weak spot...I would change everything around 5K just to be safe.

exactly. My point exactly:D

I will be going to Mobil one as well. Used it in my Colorado and had the oil tested after 12K miles (keep in mind, I changed the filter every 3000 and topped off as needed, and didn't start the extended oil service until after the motor was well broken in), and was told that it was still protecting as well or better than most Mineral type oils do brand new. Itdoes break down, from heat and combustion gasses, but if you keep a clean filter in it, and top off as needed, I can see an easy service life of 10K miles out of it.

The filter truely is the weak spot... Don't buy some crappy Fram filter. they are junk. Spend the extra few dollars and get a quality filter (K&N and Delco's are pretty good) if you plan on going past 3K miles on the oil.

oil= 1.49
syn oil = 6.99
engine = 2700.00
use good oil change often save 2200 over engine life

I know a guy who only changed the filter for years using regular every 3K and topping it off. He kept the car for several years and over 150K miles. The filter is definitely the key.

from what ive heard, mobile one is not fully synthetic, even though it says it is.
I quit royal purple, do to some test results i have seen, and switched to amsoil 0-20 full syn, with k&n filters.
thats just my .02

I use Amsoil and read somewhere on this forum that a guy used Amsoil in the past and will never use it again (blew up engines, although they were bikes/quads/something/...) others say it's ok. Don't really know what to think about it. I didn't go for Royal Purple because that one is not according to the specs from Ford and Amsoil is...
I'll change every 5K (oil and filter)

ORIGINAL: Perdi

Synthetic does break down, just not as fast. I'm still changing mine at 3000 (Mobile 1) but only cause the car is still under 10K miles.

6-7K is fine, and you could go more...Personally I wouldn't, at least not in 'my baby' but on a POS I've gone 20K with no problems.






Yea, sounds like a truck I once had. The rings were so far gone, that the oil changed itself. I would add a qt. every 150 miles and this way, fresh oil was always in there. Only problem was I had to clean the plugs every 400 miles to keep the thing from missing. I pulled a boat once and when we launched it, you should have seen the oil slick coming from the bow.:D

I run Castrol Syntec 5W50. Awesome oil, its relatively cheap when compared to Royal Purple or Amsoil, but just as good. Never had any problems. I havent had good luck with mobil, cars run hotter, seem to rev slower, etc.
-P.
PS: Man the oil you guys are talkin bout is like water[:o] 5w20, 0w20. Maybe if you drive like a granny would I ever run oil that is that thin.

ORIGINAL: P Zero

I run Castrol Syntec 5W50. Awesome oil, its relatively cheap when compared to Royal Purple or Amsoil, but just as good. Never had any problems. I havent had good luck with mobil, cars run hotter, seem to rev slower, etc.
-P.
PS: Man the oil you guys are talkin bout is like water[:o] 5w20, 0w20. Maybe if you drive like a granny would I ever run oil that is that thin.





It is THAT thin so that it saves a little gas, and circulates faster for the upper valvetrain. Remember.......................thinner oil means better circulating, and thicker oil means more oil pressure. Our engines were designed for 5w20 and I am surprised you aren't blowing seals and burning valve guides.

ORIGINAL: GidyupGo

ORIGINAL: P Zero

I run Castrol Syntec 5W50. Awesome oil, its relatively cheap when compared to Royal Purple or Amsoil, but just as good. Never had any problems. I havent had good luck with mobil, cars run hotter, seem to rev slower, etc.
-P.
PS: Man the oil you guys are talkin bout is like water[:o] 5w20, 0w20. Maybe if you drive like a granny would I ever run oil that is that thin.





It is THAT thin so that it saves a little gas, and circulates faster for the upper valvetrain. Remember.......................thinner oil means better circulating, and thicker oil means more oil pressure. Our engines were designed for 5w20 and I am surprised you aren't blowing seals and burning valve guides.


But, you have to understand that as oil gets hotter it gets thinner. Like I said before, you must drive like a grandma and your car must not get very hot. I tend to drive the wheels off cars so they get HOT! The thicker the oil the more it can lubricate at higher temps, and resist thermal breakdown.
And 5w50 is by no means a "thick" oil. It "acts" like a 50 weight oil when it gets hot, which is exactly what I want it to do, but when its cold it "acts" like a 5 weight and gets to where it need be.

Regardless, you should check your owners manual for what weight of oil should be in there for "SEVERE DUTY USAGE". Severe duty is usually extreme temperature changes (climate), or hauling, etc.. Since mustangs are usually driven harder than most cars they fall into that catagory. Youll notice in the owners manual, itll suggest that you run a thicker oil for exactly that purpose.

5w20 or 0w20 is great for mom in her familay sedan, but in a performance perspective its not so good. Itll literally have as much viscosity as water when hot, which is WAY too thin. Thats where youll experience valvetrain failure. But hey its your car, do what you want.
-P.
PS: My car doesnt leak 1 drop of oil and it had cork valve cover gaskets [8D].

ORIGINAL: P Zero

ORIGINAL: GidyupGo

ORIGINAL: P Zero

I run Castrol Syntec 5W50. Awesome oil, its relatively cheap when compared to Royal Purple or Amsoil, but just as good. Never had any problems. I havent had good luck with mobil, cars run hotter, seem to rev slower, etc.
-P.
PS: Man the oil you guys are talkin bout is like water[:o] 5w20, 0w20. Maybe if you drive like a granny would I ever run oil that is that thin.





It is THAT thin so that it saves a little gas, and circulates faster for the upper valvetrain. Remember.......................thinner oil means better circulating, and thicker oil means more oil pressure. Our engines were designed for 5w20 and I am surprised you aren't blowing seals and burning valve guides.


But, you have to understand that as oil gets hotter it gets thinner. Like I said before, you must drive like a grandma and your car must not get very hot. I tend to drive the wheels off cars so they get HOT! The thicker the oil the more it can lubricate at higher temps, and resist thermal breakdown.
And 5w50 is by no means a "thick" oil. It "acts" like a 50 weight oil when it gets hot, which is exactly what I want it to do, but when its cold it "acts" like a 5 weight and gets to where it need be.

Regardless, you should check your owners manual for what weight of oil should be in there for "SEVERE DUTY USAGE". Severe duty is usually extreme temperature changes (climate), or hauling, etc.. Since mustangs are usually driven harder than most cars they fall into that catagory. Youll notice in the owners manual, itll suggest that you run a thicker oil for exactly that purpose.

5w20 or 0w20 is great for mom in her familay sedan, but in a performance perspective its not so good. Itll literally have as much viscosity as water when hot, which is WAY too thin. Thats where youll experience valvetrain failure. But hey its your car, do what you want.
-P.
PS: My car doesnt leak 1 drop of oil and it had cork valve cover gaskets [8D].





You have it backwards. With todays multi viscous oil, it starts out thin and gets thicker as it heats up. Our GT motors don't need or want anything other than 5w20 as stated in the owner's manual regardless of how they are driven.

For me it is Redline 5w-30 and 8 ounces "Tufoil" every 5k miles. Previous vehicle I changed every 4k miles.

Critical factor is the driving you do. Short distance stop and go worse on oil, long distance commute better on oil. If I recall correctly it takes about 20 minutes for the oil to get to ops temp and to start cleaning out contaminants. 85% of your engine wear comes from engine starts with "Dino" oil, Synthetic adhere better to parts, alleviating that problem somewhat.

Years ago I new an old mechanic who did the whole nine yards with engines. Back in "Dino" oil times. His policy was to built an engine and use 10w, when it started using oil, switch to 20w, till he got to 50w, then rebuild engine again.

ORIGINAL: algregory

For me it is Redline 5w-30 and 8 ounces "Tufoil" every 5k miles. Previous vehicle I changed every 4k miles.

Critical factor is the driving you do. Short distance stop and go worse on oil, long distance commute better on oil. If I recall correctly it takes about 20 minutes for the oil to get to ops temp and to start cleaning out contaminants. 85% of your engine wear comes from engine starts with "Dino" oil, Synthetic adhere better to parts, alleviating that problem somewhat.

Years ago I new an old mechanic who did the whole nine yards with engines. Back in "Dino" oil times. His policy was to built an engine and use 10w, when it started using oil, switch to 20w, till he got to 50w, then rebuild engine again.


Miss type, met 5w-20 Redline

ORIGINAL: algregory

For me it is Redline 5w-30 and 8 ounces "Tufoil" every 5k miles. Previous vehicle I changed every 4k miles.

Critical factor is the driving you do. Short distance stop and go worse on oil, long distance commute better on oil. If I recall correctly it takes about 20 minutes for the oil to get to ops temp and to start cleaning out contaminants. 85% of your engine wear comes from engine starts with "Dino" oil, Synthetic adhere better to parts, alleviating that problem somewhat.

Years ago I new an old mechanic who did the whole nine yards with engines. Back in "Dino" oil times. His policy was to built an engine and use 10w, when it started using oil, switch to 20w, till he got to 50w, then rebuild engine again.






I used to use straight 30w back then. If you got 100,000 miles on a car, you figured you got your money's worth. I usually got way over that before I would sell it off and the thing was still a good car.

ORIGINAL: GidyupGo

ORIGINAL: P Zero

ORIGINAL: GidyupGo

ORIGINAL: P Zero

I run Castrol Syntec 5W50. Awesome oil, its relatively cheap when compared to Royal Purple or Amsoil, but just as good. Never had any problems. I havent had good luck with mobil, cars run hotter, seem to rev slower, etc.
-P.
PS: Man the oil you guys are talkin bout is like water[:o] 5w20, 0w20. Maybe if you drive like a granny would I ever run oil that is that thin.





It is THAT thin so that it saves a little gas, and circulates faster for the upper valvetrain. Remember.......................thinner oil means better circulating, and thicker oil means more oil pressure. Our engines were designed for 5w20 and I am surprised you aren't blowing seals and burning valve guides.


But, you have to understand that as oil gets hotter it gets thinner. Like I said before, you must drive like a grandma and your car must not get very hot. I tend to drive the wheels off cars so they get HOT! The thicker the oil the more it can lubricate at higher temps, and resist thermal breakdown.
And 5w50 is by no means a "thick" oil. It "acts" like a 50 weight oil when it gets hot, which is exactly what I want it to do, but when cold it "acts" like a 5 weight and gets to where it need be.

Regardless, you should check your owners manual for what weight of oil should be in there for "SEVERE DUTY USAGE". Severe duty is usually extreme temperature changes (climate), or hauling, etc.. Since mustangs are usually driven harder than most cars they fall into that catagory. Youll notice in the owners manual, itll suggest that you run a thicker oil for exactly that purpose.

5w20 or 0w20 is great for mom in her familay sedan, but in a performance perspective its not so good. Itll literally have as much viscosity as water when hot, which is WAY too thin. Thats where youll experience valvetrain failure. But hey its your car, do what you want.
-P.
PS: My car doesnt leak 1 drop of oil and it had cork valve cover gaskets [8D].





You have it backwards. With todays multi viscous oil, it starts out thin and gets thicker as it heats up. Our GT motors don't need or want anything other than 5w20 as stated in the owner's manual regardless of how they are driven.


No I dont, perhaps you misread it let me put in bold for you.
-P.

The problem with any oil is the contaminants it picks up from blow by etc. If you could filter that out while running, you could go considerably longer between oil changes. Problem is, the more filtration, the less flow you get through the filter. While changing the filter every so often may be a good thing, I prefer to change oil and filter every 5000 miles using Mobil 1. I used either Pennzoil synthetic or Mobil 1 in my 2000 V6 and it didn't leak or use a drop after 177,000 miles. It'd still been running if it wasn't attacked by a telephone pole.

ORIGINAL: dirtydeedsinc

It'd still been running if it wasn't attacked by a telephone pole.


Those damn sneaky telephone poles, just jump out at ya.;)[8D]
-P.