My 2005 Buick Century with a 3.1 L push rod V-6 calls for 5W30 on the oil cap . My other (newer) cars specify 5W 20 . I would like to standardize on 5W 20 for all my cars and would like to know if this will cause a problem with the Buick ? To date Buick has 90K miles and no leaks . It would be easier this way to load up on just one viscosity oil when ever a good sale presents itself (i.e. NAPA Synthetic).
Can I use 5W 20 in a 2005 GM 3.1L Push Rod V6 ?
- Thread starter ChrisD46
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This has been a hotly debated topic. To summarize: it's not recommended, but you'll probably be OK.
Hi.
I would recommend against doing that.
Let's think about it. Same cars, same engines. One is older, the other is newer by year. Your old one is 5w30. Then suddenly, without changing the engine, they recommend a 5W-20 for the newer vehicle.
Ask yourself why they did that? Tighter clearances? Smaller oil holes or whatever? Yeah right.
Fuel economy? Absolutely. During in-house tests and controlled environments, lower viscosities provide lower drag = better fuel economy. Out on the open road? It's a toss because so many variables are present.
Now. This is the reason why they changed. They have evaluated the same engine under a lower viscosity oil. It shows performance and wear "within acceptable standards."
What does acceptable standards implicate? The top dogs want a certain life expectancy out of a vehicle. We engineers design to meet those requirements. Whether it's better for the consumer or better for the top dogs...hmmm.
I don't believe you will hurt your engine if you switch because it still meets acceptable standards which is why they started recommending a lower viscosity.
But let's face it really. Lower viscosity oils adhere less, as they create lower drag. This means they simply won't provide the same oil film thickness at the same operating conditions as a fluid with higher kinematic viscosity. It's important to note that most consumers don't operate in extreme conditions.
So yes. A manufacturer is after different things when they specify different things.
I'm going to compare it to motorsports. In F1 racing, we want maximum power. So, less drag = more power = low viscosity fluids specified. In endurance racing, longevity enters the equation. So, higher drag = great film stability = better protection. However, we have to find the right balance because it still needs maximum power to cross the line first. And consumer vehicles. What do people want? Fuel economy. Power. Well, most of them want these two things. Which equation does it fit nicely in? Less drag = more power = greater fuel economy = lower viscosity fluids.
This is more of a post about my opinions haha. No offense!
I would recommend against doing that.
Let's think about it. Same cars, same engines. One is older, the other is newer by year. Your old one is 5w30. Then suddenly, without changing the engine, they recommend a 5W-20 for the newer vehicle.
Ask yourself why they did that? Tighter clearances? Smaller oil holes or whatever? Yeah right.
Fuel economy? Absolutely. During in-house tests and controlled environments, lower viscosities provide lower drag = better fuel economy. Out on the open road? It's a toss because so many variables are present.
Now. This is the reason why they changed. They have evaluated the same engine under a lower viscosity oil. It shows performance and wear "within acceptable standards."
What does acceptable standards implicate? The top dogs want a certain life expectancy out of a vehicle. We engineers design to meet those requirements. Whether it's better for the consumer or better for the top dogs...hmmm.
I don't believe you will hurt your engine if you switch because it still meets acceptable standards which is why they started recommending a lower viscosity.
But let's face it really. Lower viscosity oils adhere less, as they create lower drag. This means they simply won't provide the same oil film thickness at the same operating conditions as a fluid with higher kinematic viscosity. It's important to note that most consumers don't operate in extreme conditions.
So yes. A manufacturer is after different things when they specify different things.
I'm going to compare it to motorsports. In F1 racing, we want maximum power. So, less drag = more power = low viscosity fluids specified. In endurance racing, longevity enters the equation. So, higher drag = great film stability = better protection. However, we have to find the right balance because it still needs maximum power to cross the line first. And consumer vehicles. What do people want? Fuel economy. Power. Well, most of them want these two things. Which equation does it fit nicely in? Less drag = more power = greater fuel economy = lower viscosity fluids.
This is more of a post about my opinions haha. No offense!
Chris,
I'd wait until someone familiar with that engine has an opinion.... not to let BITOG'ers theorys to get in the way of facts.
I wish I was more help. Toyota has a handy reference chart for what is back specd, maybe GM does too.
I'd wait until someone familiar with that engine has an opinion.... not to let BITOG'ers theorys to get in the way of facts.
I wish I was more help. Toyota has a handy reference chart for what is back specd, maybe GM does too.
Originally Posted By: sangyup81
It's much safer to go 5w30 if you want to standardize
+1
Your newer engine that now takes 5w20 was probably spec'ed on 5w30 a few years ago. What car is it?
It's much safer to go 5w30 if you want to standardize
+1
Your newer engine that now takes 5w20 was probably spec'ed on 5w30 a few years ago. What car is it?
dtt004, i think that was well versed opinion or not, and well educated, not to mention made commonsense, and no doubt the epa plays a BIG role in reccomendations of oil specs used in the USA.
as youll notice many of the same engines in other countries spec way different oils. but as for me and my opinion, unless youre towing, have a turbo charged engine etc, 5w20 is a great choice for a 4 or 6 cylinder natually aspirated car (modern), infact ive noticed the thinner it seems the smoother the engine runs, some will say its all in my head, but when i switched my wifes 08 escape 2.3l to edge 5w20 (known to be on the thin side) it runs quiter and smoother than ever.
as youll notice many of the same engines in other countries spec way different oils. but as for me and my opinion, unless youre towing, have a turbo charged engine etc, 5w20 is a great choice for a 4 or 6 cylinder natually aspirated car (modern), infact ive noticed the thinner it seems the smoother the engine runs, some will say its all in my head, but when i switched my wifes 08 escape 2.3l to edge 5w20 (known to be on the thin side) it runs quiter and smoother than ever.
Thanks all - other cars are 2010 Hyundai Elantra 4 cyl. which was back spec'd for 5W 30 a few years ago . Next is a 2007 Kia Sedona 3.8L V-6 which states it could use 5W 30 if necessary in the manual . Two reasons for leaning towards 5W 20 are : 1 ) MC Syn Blend 5 qt. jugs at WM (no 5W 30 offered) 2 ) Belief that 5W 20 is more stable than 5W 30 (I could be wrong) . On the other hand , I don't want to wear out the Buick pre-maturely with a switch to 5W 20 (if that is possible) Additional comments ?
I have three vehicles in my fleet, one calls for 5W30, another calls for 5W30 and was back spec'd to 5W20, and the newest 5W20. It would be very easy for me to use 5w20, or 5W30 in all three vehicles. I use what is spec'd, which means two different grade oils. It really isn't a big deal. Use what the engine was spec'd for.
As a side note the vehicle that was back spec'd to a 20 grade from a 30 grade runs better with a 20 grade and uses a little less oil when the sump is full with a 20 grade oil.
20 grade oils were extensively tested they are not going to ruin an engine calling for it, even if a prior year engine called for a 30 grade oil. Johnny commented about this just the other day here is what he had to say.
Quote: It is really quite simple, if the manufacture recommends it, use it, with full confidence, even in hot weather. Heck, my son's Element is approaching 165,000 miles on nothing but 5W-20 Pennzoil doing 5K oil changes, and it does not use a drop of oil between changes and runs like a top.
I was very privileged to be in Dearborn, MI when Ford Motor Company was doing their long term testing on 5W-20 oils in the 4.6L engines. The engines I saw torn down after way over 250,000 miles of some pretty intense testing were amazingly clean and well within tolerances.
Sure, if I had a $100,000 European Exotic I would use the heavier oils they recommend.
I will let you know when my cars wear out on 5W-20. And just for arguments sake, most 5w30 oils shear down to a 5W-20 before their life is over. Most 5W-20 oils are pretty shear stable.
As a side note the vehicle that was back spec'd to a 20 grade from a 30 grade runs better with a 20 grade and uses a little less oil when the sump is full with a 20 grade oil.
20 grade oils were extensively tested they are not going to ruin an engine calling for it, even if a prior year engine called for a 30 grade oil. Johnny commented about this just the other day here is what he had to say.
Quote: It is really quite simple, if the manufacture recommends it, use it, with full confidence, even in hot weather. Heck, my son's Element is approaching 165,000 miles on nothing but 5W-20 Pennzoil doing 5K oil changes, and it does not use a drop of oil between changes and runs like a top.
I was very privileged to be in Dearborn, MI when Ford Motor Company was doing their long term testing on 5W-20 oils in the 4.6L engines. The engines I saw torn down after way over 250,000 miles of some pretty intense testing were amazingly clean and well within tolerances.
Sure, if I had a $100,000 European Exotic I would use the heavier oils they recommend.
I will let you know when my cars wear out on 5W-20. And just for arguments sake, most 5w30 oils shear down to a 5W-20 before their life is over. Most 5W-20 oils are pretty shear stable.
Originally Posted By: addyguy
I wouldn't.
GM 60-degree V-6's are all potentially prone to IM gasket leaks. I'd want that extra bit of viscosity to protect the engine. Yeah, it's not much, but those engines have so many 'issues', I wouldn't want thin oil in them.
+1
This. My old 3.1 did just fine of a diet of 5w30. It did end up with 5w20 in it is (belle tire screw up), it while it didn't hurt it, I noticed it did drive a bit different....
I wouldn't.
GM 60-degree V-6's are all potentially prone to IM gasket leaks. I'd want that extra bit of viscosity to protect the engine. Yeah, it's not much, but those engines have so many 'issues', I wouldn't want thin oil in them.
+1
This. My old 3.1 did just fine of a diet of 5w30. It did end up with 5w20 in it is (belle tire screw up), it while it didn't hurt it, I noticed it did drive a bit different....
Originally Posted By: daves87rs
Originally Posted By: addyguy
I wouldn't.
GM 60-degree V-6's are all potentially prone to IM gasket leaks. I'd want that extra bit of viscosity to protect the engine. Yeah, it's not much, but those engines have so many 'issues', I wouldn't want thin oil in them.
+1
This. My old 3.1 did just fine of a diet of 5w30. It did end up with 5w20 in it is (belle tire screw up), it while it didn't hurt it, I noticed it did drive a bit different....
I have a 3.1 in my Buick and I wouldn't use 5W20 for the reasons previously mentioned.
If you are set on standardizing your oil then use Edge or Havoline dino which are close to 5W20s but still meet your OE recommendation.
I have often run 10W30 in summer without any noticeable effects but I wouldn't have the
gonads to run 5W20.
Originally Posted By: addyguy
I wouldn't.
GM 60-degree V-6's are all potentially prone to IM gasket leaks. I'd want that extra bit of viscosity to protect the engine. Yeah, it's not much, but those engines have so many 'issues', I wouldn't want thin oil in them.
+1
This. My old 3.1 did just fine of a diet of 5w30. It did end up with 5w20 in it is (belle tire screw up), it while it didn't hurt it, I noticed it did drive a bit different....
I have a 3.1 in my Buick and I wouldn't use 5W20 for the reasons previously mentioned.
If you are set on standardizing your oil then use Edge or Havoline dino which are close to 5W20s but still meet your OE recommendation.
I have often run 10W30 in summer without any noticeable effects but I wouldn't have the
gonads to run 5W20.
First 10w30 was too thick and now you people are saying 5w30 is too thick. I'd advise all of you to heat up 10w30 in a pan on the stove -- get it up to 200 degrees Fahrenheit and then tell me how thick it is.
Originally Posted By: ChrisD46
Thanks all - I have come to the conclussion it's not worth experimenting with something that isn't broken ! I'll continue with a 5W 30 in the Buick ...
+1 use what was spec'd, unless GM back spec'd the engine. It would also make my life easier to use one grade oil too, but my 4.9 I6 calls for 30 grade oil and that's what it gets.
Thanks all - I have come to the conclussion it's not worth experimenting with something that isn't broken ! I'll continue with a 5W 30 in the Buick ...
+1 use what was spec'd, unless GM back spec'd the engine. It would also make my life easier to use one grade oil too, but my 4.9 I6 calls for 30 grade oil and that's what it gets.
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Originally Posted By: ChrisD46
My 2005 Buick Century with a 3.1 L push rod V-6 calls for 5W30 on the oil cap . My other (newer) cars specify 5W 20 . I would like to standardize on 5W 20 for all my cars and would like to know if this will cause a problem with the Buick ? To date Buick has 90K miles and no leaks . It would be easier this way to load up on just one viscosity oil when ever a good sale presents itself (i.e. NAPA Synthetic).
Your GM may have a magnetic drain pan bolt. See if metallic shavings are attracted to the bolt when draining the 20W oil.
My 2005 Buick Century with a 3.1 L push rod V-6 calls for 5W30 on the oil cap . My other (newer) cars specify 5W 20 . I would like to standardize on 5W 20 for all my cars and would like to know if this will cause a problem with the Buick ? To date Buick has 90K miles and no leaks . It would be easier this way to load up on just one viscosity oil when ever a good sale presents itself (i.e. NAPA Synthetic).
Your GM may have a magnetic drain pan bolt. See if metallic shavings are attracted to the bolt when draining the 20W oil.
some people reported on here their vehicles are quieter and smoother etc. on the 5W20. where 5W30 is spec.
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