[Bammerman]

My oil is down to 5%, per my Volt, so I've been trying to decide where to have it changed. My Chevy dealer is a 20-minute drive away and advertises an oil change, etc. deal that includes ACDelco dexos1 Full Synthetic. My local garage, that I've used for years and trust, says they always use whatever the manufacturer specifies and it will be dexos1, but not full synthetic (unless I'm willing to pay a lot extra). And the Volt's manual actually says "ACDelco dexos1 Synthetic Blend is recommended" -- emphasis on "blend", not "full synthetic". So please help me out here: should I demand "full synthetic" or "synthetic blend" or just be happy with dexos1?

 

[Elemental]

First question -

When you hear "semi synthetic" and "fully synthetic", what do you hear, with respect to oil?

 

[Bammerman]

First question -

When you hear "semi synthetic" and "fully synthetic", what do you hear, with respect to oil?

Well, maybe that it's all just BS, but then that tends to be my first reaction generally. No, your question sailed over my head, unfortunately.

 

[turnbowm]

Take it to a Volt-authorized Chevy dealer where they are trained to properly service and inspect the car.

 

[2015 volt]

most Chevrolet dealers herein florida give you lifetime free oil changes,and I gladly use their services
remember,our volt's sit lower to the ground,and most oil change facilities will be hard for you're volt to enter the shop,depending on the lift they use.

 

[Elemental]

Well, maybe that it's all just BS, but then that tends to be my first reaction generally. No, your question sailed over my head, unfortunately.

That's ok. Tribology is a topic that's way more deep than a post on a car forum. But, for your question let try to give a consolidated answer.

The term "Synthetic" has ZERO meaning with relation to oil, outside of advertising. Oil base stocks are graded on a level of 1-5...1 being **** (20-50s,10-40s) and level 4 being top shelf (ACEA E1-5 type stuff). Level 5 as a catch all that doesn't fit the other stuff.

Most oils, including those labeled Semi are level 2 base stocks, if I had to guess, GMs Synthetic is a level 3. Level 4s *tend* to be reserved for the euro spec stuff.

DEXOS is an invention of standardizing a spec. At one time, GM had 4 different 5-30 ratings. THis created confusions and engine failures. Its easier to say "THis is for gas" and "THis is for gas and Diesel"..... Thus dexos 1 and 2.


So, to answer your question...... Based on what I know, either will work fine... The algorithm is set for a Dexos spec oil, so I would look more to does the oil meet that spec than if its "Semi" or "Full"

 

[wws]

That's ok. Tribology is a topic that's way more deep than a post on a car forum. But, for your question let try to give a consolidated answer.

The term "Synthetic" has ZERO meaning with relation to oil, outside of advertising...

Unfortunately, ever since Mobil lost that lawsuit to Castrol, the definition of "synthetic" has been weakened considerably. Mobil-1 used true synthetic PAO base stocks, whereas Castrol used super-refined dino base stocks to achieve much the same results. The courts allowed Castrol to continue using the term "synthetic".

And how much "synthetic" is actually in a "semi-synthetic blend". 5%? 50%? 90%?

So, to answer your question...... Based on what I know, either will work fine... The algorithm is set for a Dexos spec oil, so I would look more to does the oil meet that spec than if its "Semi" or "Full"

Good advice.

 

[BAZINGA]

I'd recommend your local Chevy dealer, prices are competitive and they can check to see if there are any software, TSB's or open recalls on your car while they have it and since it's a once a year visit they rotate the tires and re-learn the TPMS'.

And since the ICE in my Volt's operate so seldom I opt for full synthetic Mobil 1. I do get a $25 price cut as my dealer loads up a pre-paid account with $500 for service and accessories.

 

[FMinMI]

Just use a name brand oil that shows it meets dexos1 requirements (it will be printed on the container) and you are fine. Also make sure to change it based on either the % oil life OR the time period specified in the manual (mine says at least every 2 years), which ever comes FIRST.

 

[Bammerman]

I did go to the Chevy dealer, mostly because he could fit me in sooner.

But I am reminded of my first car, a '61 Rambler wagon of a hideous orange color that I bought for $300 about 1969 or so, of which one could say to the station attendant, "Fill 'er up with oil and check the gas." On a trip north to Vermont the seat broke and I took it to a country welder to fix, and he set the seat stuffing on fire with his torch. A small smoky fire quickly put out. Later, driving that car in a Vermont winter blizzard, the wipers gave out, but fortunately I had a steel kitchen spatula with me (along with all my other worldly belongings) and so I drove with my right hand on the wheel and my left out the window scraping ice and snow off the windshield. I still remember the look a Vermont State Trooper gave me. I eventually gave the car to a good friend when I went out of the country and she drove it for a year or so... when a mechanic told her the car's chassis had a crack in it from stem to stern.

 

[FMinMI]

...I eventually gave the car to a good friend when I went out of the country and she drove it for a year or so... when a mechanic told her the car's chassis had a crack in it from stem to stern.

You gave this car to a "good friend"??? Shame on you

Living in MI, and having very cold winters and wide temperature fluctuations, I change my oil yearly regardless of % oil status as the limited/cycled engine use doesn't allow it to get up to temp and stay there for long periods of time, and you can / do get moisture 'build up' in the oil. Not good at all. You see it as an oily foam when you open the oil cap. So, every spring it gets changed. My % meter never got below 50% but I don't care - I want the engine to last and $20-30 once a year (I do it myself) is cheap insurance...

 

[Bammerman]

Well heck, I didn't know the chassis was cracked! And this was 42 years ago and I had no money! Nor did she, and she got a car for free. Worth every penny, too.

 

[PittIsIt]

I bought the car used - Have put 4100 miles on (mostly EV), and the tires needed rotation. Indicator said 17% left so I decided to go ahead and change out the oil for the first time for me.

(2013 with 39000 miles)

I went to my local Firestone because I can walk back to work after dropping it off (I hate waiting for anything). I asked for full synthetic and they said it was dexos certified.

I've noticed when the ICE does run now, it is quieter. I am wondering if Previous Owner used synthetic and premium fuel - because the car is different now that I am doing that. (When running ICE).

I don't go to dealer because I have no incentive to - and I trust my firestone guys. They have always been good to me.

 

[El Dobro]

If the oil is on this list, it's Dexos 1 approved.
http://www.centerforqa.com/dexos-brand1/