How often to change Synthetic Oil.

[HMFDZ28]

I have the RP filter on both my Camaro and my truck and havent had an issue with either.

As far as when I change my oil... I follow the mileage (its usually around 5k) and oil pressure. When I notice my pressure is lower then I like I change it; I think thats the most important. I like the needle on my truck sitting round 40 psi at idle... and so it shall stay.

 

[Cobra]

I always tought the computer was set around 7k. Either way I currently running Mobil 1 full syn. and still stick to 3k to 4k. Usually closer to 3. I know I can go longer but just prference.

 

[Abn Panzer]

3K-4K... Out of Habit

I've allways kind of floated between the Synthetics, depending on what was on sale at the time.

Had also been using the K&N oil filters... that is until last night when I read the Filter reviews, posted earlier in this thread. I am aparently a sucker for advertising and 'recommendations based on ignorance from some sales people'. Anyone have a bridge for sale?

 

[Z15]

I always tought the computer was set around 7k.

No its not based on mileage or sampling of the oil. Its a computer algorithm that takes in account engine starts, rpms, engine temps and other factors determined by years of testing, in other words driving habits. The more stop and go driving you do, the sooner the OLM will trigger, drive all highway miles and you could go a year and more than 10,000 miles before that happens. OLM are only calibrated for synthetic oil in car that come factory filled with synthetic oil like all Cadillacs since 2005, all Corvette's since the early 1990 and starting in 2011 models you will be required to use a synthetic.

How much oil is lost changing just the filter, a qt or less.


People really think that If it says full or fully synthetic on the bottle that they actually really get a real synthetic oil in this country . All the oil company synthetic's are derived from petroleum base stocks. There are only about 3 main companies making a true synthetic. That is an oil engineered molecule by molecule rather than refined by a special process call hydro-cracking.

Why do they call them synthetics then?
In 1999 - Mobil filed a complaint with the National Advertising Division of the Better Business Bureau in the US claiming that Castrol was engaging in false advertising by calling Syntec "full synthetic" since it was now being made with Group III base oil. (Google it you will find its from petroleum.) Castrol was able to present enough "evidence" to convince the *** that Group III base oil could legitimately be called synthetic, so they rulled in Castrol's favor. This ruling has no "legal" standing. It merely means that as far as the *** is concerned, an oil company is not falsely advertising an oil as "full synthetic" if that oil is made from Group III petroleum base oil. So in other words, the oil companies are using the term synthetic to sell you high priced petroleum oils. They might be better than oils that preceded them buy still are a long way from the true Gr. IV synthetics, some which have been on the market since 1972 (AMSOIL).

 

[redemn93]

so is mobil 1 full synthetic?

i go between mobil 1 and penzoil "full synthetic".

once i get change oil message in my 01 tahoe i look at the oil. its usually still clean so i wait a little longer. if oil pressure is good and the oil is clean...its still good oil.

 

[Z15]

No, those 2 oils you mention are a Group III synthetic. All the only company synthetics are Gr. III base oils. The only Mobil oil that is a real 100% synthetic is the Mobil 1 Extended Performance oil. The term Full or Fully synthetic is the tip-off, they will never say 100% because it cannot be and still come from refined crude oil.

Of course you are going to get a awful lot of arguments to the contrary from loyal Mobil 1 users and others who have limited knowledge of oil formulations. Real synthetic oils are not cheap to make so you will not find them selling at discount prices.

Hydrocracked/Hydroisomerized = API Group III base oils. Chevron, Shell, and other petrochemical companies developed processes involving catalytic conversion of feed stocks under pressure in the presence of hydrogen into high quality mineral lubricating oil. In 2005 production of GTL (Gas-to-liquid) Group III base stocks began. The best of these perform much like polyalphaolefin.

Group III base stocks are considered synthetic motor oil ONLY in the United States. Group III based lubricants are not allowed to be marketed as "synthetic" in any market outside of the USA.

 

[redemn93]

good info. thanks. i still like my mobil 1. my engines are always so clean when i open them up for one reason or another.

so i guess, theoritically, fully synthetic oil will one day be cheaper the mobil 1, etc as crude oil prices keep going up.

 

[Z15]

The oil might be synthetic but the energy used to produce it and to transport it is not so everything hinges on the price of crude.

 

[Tdub]

Is it okay to switch over to this oil if you have 140k rounds?

 

[07Denali]

Is it okay to switch over to this oil if you have 140k rounds?

From all that I have read, yes. But, do not go back and forth. Change to synthetic and stay with synthetic. The only thing that I do remember is that I was always told to "break in" motor with regular dead dino as the rings need it to seal and seat properly.

I am by no means a petroleum engineer, just what I have read from all those that are supposedly smarter than I am.

I run 0w-30 Mobil one in all of my cars/trucks. I got turned on to it by Toyota as that is what is in the Lexus and that is what you have to use to keep the CEL off. Any heavier and they insist that it will slow the valvetrain down and cause the light to come on. I got an updated maintence manual in the mail from Toyota right after I bought the car new and the only change was taking the oil change interverals to 10,000 miles. I change my car myself at 10,000, 95% highway miles, and most people I know (even car guys) would take the oil and put it right back in, it is that clean.

 

[Z15]

You can switch to a synthetic at any mileage providing the engine is in good mechanical condition. Switching to a synthetic will not hurt anything BUT will it be cost effective to switch at that many miles? One of the many benefits of synthetic oils are that the prolong engine life But in reality many engines with that amount of miles have seen their better days.

Installing new synthetic oil in a high mileage motor may not be able to handle the left over sludge and deposits, and the new lubricant soon becomes dirty with all the deposits and possibly sludge left behind from years of using petroleum oils. I would recommend that you use a engine flush product to clean out the engine prior to adding new oil such as a synthetic. There are several on these on the market, Something like this.


There is no reason that you cannot switch back and forth, that is myth that you cannot do that. Oil is oil, the engine really can't tell which is being used.

 

[Eagle]

cheaper than that is 1 quart of ATF.

 

[Z15]

That's an oil mechanics myth, born out the usual obsession to find something cheaper. But in reality, ATF is not recommended to be used in an engine no more that engine oil should be used in a automatic transmission.

ATF is just hydraulic oil and contains very little detergents compared to motor oil. Engine oil is formulated to have very low friction properties while ATF is formulated with high friction properties for the clutch pac's in the trans to function. Dexron type ATF has a viscosity in the 5-7 range (VI-III) so it a very lite hydraulic oil and because it is thin, people think its doing something good by adding to the engine oil. But the average qt of engine oil has much more cleaning abilities that any qt of ATF.

IMO putting ATF in the engine is liking play Russian Roulette. Especially with modern ATF's. Back in the old days, they were not that far apart but today contain many different additives that can be harmful to engines. Dexron VI is not even recommend for manual transmission's that have used ATF in the past because they can be harmful to seals used in those gearcase's.

 

[Eagle]

actually it has dispersants which help keep contaminants suspended while draining the oil.
No one says to drive around with atf in the crankcase.

it is a much better lubricant than KEROSENE/Diesel (though poorer solvent of course) which is the genuine OG way of doing it, and is the main ingredient of many engine flush products.




These vehicles are new enough that the oil used shouldn't have formed any deposits if changed regularly. Plus the capacities are large enough, and the oil cooling ability high enough, that the oils should NOT have had sludge problems, unlike certain 3.5 quart of oil v8s from certain import manufacturers.

Switch to synth if you want with no 'prep' needed. I noticed a bit more noise during cold weather start ups, as compared to dino. Now that the weather is mild to hot, no noise.

I also noted a small change for better mpg. nothingmajor but enough to pay for the extra cost.

jsut not happy about the undersized filters.

 

[dropmech]

The computer is a good guideline, it uses hours, rpm and load to calculate oil life expectancy.

Until the computer resets the hours on you unexpectedly as it did with mine. I have 47 hours on my hoe with 80k miles on it now. That averages to just over 1700 miles an hour!

 

[Eagle]

That is AWESOME.
has tp be the fastest Tahoe on the boards!
I am sure you remember about when you changed it, so do the ~4 months change or 5,000 mile change.

 

[ypsetihw]

in my 1.8t 4 cyl jetta I use mobil 1 0w-40 and get near 10k to the oil change . . . it all depends on how much you wanna invest. go to midas and get an oil change for $20, and you prolly need another change as soon as you pull outta the parking lot. on the other hand, put some good mobil 1 synthetic and a better than OEM filter, and you'll get 5k+ no problem.

in the long run you'll save money with good oil because you won't foul the engine as much and you'll have to change it less often, which more than offsets the added cost