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Switching to synthetic blend oil?

I have a 06 Pontiac G6 purchased at 117,000 now at 129,000 miles . I’ve been using premium convential oil , was thinking about switching to a synthetic blend since temps are dropping and less frequent oil changes . I’m at 3000 miles and my oil life is only at 50% so I think synthetic oil was used from the start . Problem is I have to add around a half a quart of oil every 2-4 weeks but there is no sign of leaks so im guessing its just burning oil . Question is will it be fine to switch to a synthetic blend ? Thanks

You can switch to synthetic blend or full synthetic oil and back to regular oil anytime.

They’re compatible.

But if you go with a synthetic blend oil, look on the bottle.

Nowhere does it say how much of the oil is regular oil and synthetic oil

And also remember, a synthetic blend oil is only as good as it’s lesser component. Which is the regular oil.


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Yeah your right

Probably better off just switching to a full synthetic and see how that goes I was thinking Castrol EDGE high mileage full synthetic


My 97 Accord with 215,000 miles has seen nothing but high mileage 5W-30 regular oil.


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Just figured it would be better lol

What brand do you use , Pennzoil high mileage convential

Agree with 100% Tester. My wife’s 87 Accord and her 96 Accord both went well past 300k miles with nothing but conventional motor oil. Her 07 Lexus has about 200k miles and it too has only seen conventional motor oil.

You bought a used vehicle with quite a few miles on it. Who know what has been used for oil in the past . Just use a brand name conventional High Mileage oil and find something else to obsess over. Myself I would probably use 10W30 on sale and drive on.


It is better, but may not be needed. I use synthetic in my Highlander (and my 05 4runner) because I tow a lot in the summer to go camping and we use the highlander to go skiing in white mountains where it’s not unheard of to drive back home when temps are -30.

Synthetics are probably a little better in engines which are designed for either. How much better, hard to say. My main caution when switching to synthetics is to not buy into the idea to extend the oil change interval. I suggest to stick with the same oil change interval you used with the conventional oil.

The oil life monitor has no way to determine what type of oil is being used. Its calculations are based on using the type of oil specified in the owner’s manual, in addition to various parameters of engine use.

Discussions and debates over engine oils have gone on for at least 60 years. The late Tom McCahill, who did car tests and wrote a monthly column for Mechanix’s Illustrated had a lot to say about motor oils in his book published in the early 1960s titled “What You Should Know About Cars”. He didn’t like multi-viscosity oil. He said that 10W-30 was a lousy number 10 and a lousy number 30". He thought its real purpose was that it saved shelf space in service stations as the station didn’t have to stock as many single viscosity oils. He had this to say about detergent oils:“I prefer detergent in my bathtub as opposed to having it in my crankcase”. He claimed to use single viscosity oil and ran one weight higher than recommended. He said he took more time to warn up the engine and he claimed to never had an engine that used oil in less than 80,000 miles.
Well, times have really changed in 60 years. Today, 80,000 miles is nothing on a modern engine. Nobody uses non-detergent single viscosity oil any more. Today’s discussion is whether or not to use synthetic oil or regular oil. I do remember my dad put detergent oil in the 1949 Dodge he owned and the oil consumption increased drastically. I experimented and put synthetic oil in my old lawnmower and the synthetic oil reduced oil consumption by 75% for two mowing seasons.
Lest one thinks the debate about synthetic.oil vs regular oil is limited to internal combustion engines, there is a debate going as to whether one should use synthetic rotor oil or regular petroleum based oil on French horn valves. I attended a horn clinic a couple of years ago and the presenter warned against using both synthetic rotor oil and using regular petroleum based oil at the same time as these oils aren’t compatible. Yet, I bought a bottle of synthetic rotor oil because nothing else was available and it worked fine. It said on the bottle of synthetic oil that it was compatible with petroleum based oils. I have used both synthetic rotor oil and regular petroleum based rotor oil on both my horns with no bad effects. Horn players are worse than auto buffs on debating what oil to use.

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First, your OLM has no way of knowing what kind of oil has been used. It is strictly a computer program. Second I think if you check your manual, it is going to call for 3000 mile changes. In my view you should not extend oil changes because of using synthetic. Really there is no need to use it and I just use Mobil in my G6 and I change at 50% OLM. IMHO.

I’ve also used both in my horn with no problems.

Truer words have rarely been spoken…I visited an old horn teacher who taught me when I was in middle school (I was honestly shocked 1, that he was still alive and 2, that he actually remembered me) and when I told him used both not only without completely cleaning out the instrument and mixing them together, I thought he was going to have a heart attack!!

To keep this car related and more on topic, my 09 Focus doesn’t specify dino vs synthetic in my manual so I use synthetic when I change it and dino when I top it off and I haven’t had any problems

Yes, the owner’s manual does say that, but not in the context you are thinking of. It says to change the oil within 600 miles of first seeing the “change oil soon” message, or within one year of the last oil change. It says to change within 3000 miles if the OLM is reset inadvertently. That is the only reference to 3000 miles.

@pyrolord314. On my horns, I use Al Cass fast valve oil–remove the valve slides and put a couple of drops into each valve. I lubricated under the valve caps with rotor oil. For the underside bearings on the valves I did use a point oiler filled with sewing machine oil. I now use synthetic oil on the underside bearings and under the valve caps. What amazes me is that I know horn players that forget about the underside bearings and these are the bearings that are the most critical.
On cars, I switched from regular oil to synthetic on the 2006 Uplander that I once owned and then switched back. My son now has the Uplander and it has over 200,000 miles with no problems. He uses high mileage oil which I doubt that it does anything to help.the engine, but it makes him feel like he is preserving the engine.s