Can GM Cars Go a Full Year on Full Synthetic?

Messages
11
Hi All,

I've seen similar questions but not quite the same, and the answer is usually some variation on "it depends," so I figured I'd just ask.

I have two GM cars, a 2006 GMC Yukon XL and a 2008 Pontiac Vibe. I work from home so I don't drive all that much, I'd be surprised if either one went over 5,000 miles in a year at this point. The Yukon just passed 180,000 miles and the Vibe is just over 140,000 miles. Both call for 5W-30. They've been running on high mileage dino oil, and typically I change the oil every 6 months (manual calls for a change every 5,000 miles/6 months), but it's starting to seem kind of wasteful. So, my question is, if I was to switch to full synthetic high mileage 5W-30 in each, could I let it go for 5,000 miles/1 year rather than 5,000 miles/6 months?

For context, I live in a suburb of Denver, and nothing around here is particularly close, so I just about always get the car up to full temp before getting back home. Denver is very dry, and contrary to what some might think, it's actually not very cold. Yeah, there are some cold days, but 40 and sunny is a pretty typical winter day. I drive both cars regularly, if not that frequently, neither is going to sit undriven for more than a week or two. So, I don't think moisture will be an issue. Anything else I should be concerned about? Forever ago in high school auto tech I thought they said there were additives that broke down over time, is that still the case (was it ever)?

Any advice would be greatly appreciated. Thanks!
 

JRed

Site Donor 2021
Messages
2,286
Location
Virginia
First time I went to Denver it was May or June and 95 degrees or something. I was super disappointed. Even if anything *is* near you in Denver the traffic will make sure you get up to operating temp.

That being said unless you like changing oil then 5w-30 synthetic for a year is definitely fine.
 
Messages
956
Location
Cedar City Utah
Hi All,

I've seen similar questions but not quite the same, and the answer is usually some variation on "it depends," so I figured I'd just ask.

I have two GM cars, a 2006 GMC Yukon XL and a 2008 Pontiac Vibe. I work from home so I don't drive all that much, I'd be surprised if either one went over 5,000 miles in a year at this point. The Yukon just passed 180,000 miles and the Vibe is just over 140,000 miles. Both call for 5W-30. They've been running on high mileage dino oil, and typically I change the oil every 6 months (manual calls for a change every 5,000 miles/6 months), but it's starting to seem kind of wasteful. So, my question is, if I was to switch to full synthetic high mileage 5W-30 in each, could I let it go for 5,000 miles/1 year rather than 5,000 miles/6 months?

For context, I live in a suburb of Denver, and nothing around here is particularly close, so I just about always get the car up to full temp before getting back home. Denver is very dry, and contrary to what some might think, it's actually not very cold. Yeah, there are some cold days, but 40 and sunny is a pretty typical winter day. I drive both cars regularly, if not that frequently, neither is going to sit undriven for more than a week or two. So, I don't think moisture will be an issue. Anything else I should be concerned about? Forever ago in high school auto tech I thought they said there were additives that broke down over time, is that still the case (was it ever)?

Any advice would be greatly appreciated. Thanks!
Right you are! I lived in Wheat Ridge CO and there is nothing particularly close.
 
Messages
11,704
Location
USA
Toyota says 1 year or 10k on synthetic, 6 months/5k on dino. So yes, you can go a full year on synthetic. Even the cheapest syn on sale will do :)

The Yukon has an OLM but says to change the oil every year even if the change oil light doesn't come on.
 
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Messages
18,595
Location
Michigan
Well, my Cavalier averages a year/ year and a half on a synthetic oil change. No issues at all. Even my Nox went almost 9 months between oil changes ! The two engines in those (5.3 and 1.8) are both stout engines that will run on just about anything...

So you will be just fine....
 
Messages
3,491
Location
Millbrae, CA
If you fully get then hot you can go 5K with a mineral oil. If 1-2 miles not getting hot then change at 3-5K.

No need for a syn and since most all PCMo's are part syn anyway go for it.
 
Messages
1,071
Location
Wash, DC
On my 2006 Matrix I did 5000 miles on dino, which typically took ~9 months.
I bike to work, so 2-3 drives per week plus a road trip once or twice a year.

Now with COVID, using synth in my 2017 Tucson, I'll be going over a year to reach 5000 miles.
 
Messages
166
Use it as long as the oil tells you it's still good. Probably be more worried about the filter than the oil.

As long as the oil from dipstick does not feel gritty between your fingers, should still be good, but check that every 1kmi beyond initial 7kmi on new oil.
 
Messages
8,638
Location
Texas
My recommendation would be to run a full synthetic high mileage oil 5w/30 and yes 1 year will be fine. Your current oil would actually be ok as well - I just like the extra margin of protection a full syn provides and the cost is but a few bucks more. The high mileage formulas also contain a little stronger additive package as well.
 
Go one year, do a UOA and let that help you decide.

^^^^^^^This. I run Amsoil SS 5W30 in GM vehicles for 13K+ and almost two years. I've done UOA plenty of times and have faith in my routine, but I don't have your engine or driving habits or running conditions. You may take my opinion as worth what you're paying for it, but my opinion is that you should run your (full synthetic) out to where your comfort level is, then do a UOA. Everything that everyone says is guesswork until you have UOA. Do whatever lets you sleep at night. What does your owner's manual say?
 
Messages
16,240
Location
N.H, U.S.A.
Some old labels used here that are totally irrelevant.

First "Full Synthetic" means nothing. And Dino mean nothing.

Forget that Appellation.

This 1990's categoriztion has got to stop.

Go by the Service Category and applicable Specification.

pertinent examples:

ILSAC GF-5 or -6, DEXOS 1 gen2

or ACEA A3,B4, BMW LL-01, MB 229.5, Porsche A40, VW 504.00, etc.

ILSAC GF5 and Dexos are long drain oils.

BMW LL-01 is a long drain oil of somewhat higher specification and performance than most currently marketed ILSAC N.American lubricants.

The O.P., Salvat is fine with a 1X year oil change on his/her 2 vehicles given the miles traveled and the complete sump warm-up.

I've nearly doubled the factory manual recommended drain interval on my Wife's commuter car with a much BETTER oil analysis results than the Mean of Blackstone reports for this vehicle. and I verified with a back to back analysis with a different brand oil. with the same results.

5k miles is a short interval oil change REGARDLESS of oil age.

enjoy the newfound spare time and lower cost !
-Ken
 
Messages
942
Location
Daytona Beach
Consider the 2012 Chevy Volt for a moment. The owners manual suggests an oil change every two years, or when the OLM is at ZERO.
Yes, the Volt is a different kind of car, but the engine doesn't run much, and may not even get up to temp when it does (the OLM considers this factor). It does call for Mobil1 5W-30.
 
Messages
35,785
Location
NY
Not exactly what you want to hear but here goes: It depends. Blanket statements can lead to trouble, spend a few extra $$ on your next oil change and get a UOA. Assuming your driving conditions remain about the same going forward you'll know for certain. Had I followed the one of the more popular blanket statements often touted on the board "a good synthetic oil can easily go 10K miles" I'd have problems with all three of my vehicles. Spend the money on a UOA, and eliminate the guesswork.
 
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