[TexasToughTruck]

I have a 2011 silverado 5.3L which I got around 80k miles. Ive been running Pennzoil Ultra Platinum 5w-30 Synthetic since I got it. I was looking into running a high mileage synthetic like mobile 1 high mileage full synthetic but wasn't sure If I should stick to the factory recommended 5w-30 or Ive read that some people change the oil weight in high mileage vehicles. What do you think? I have about 97k miles on it now.

Thanks in advance for your suggestions.

 

[Cowpie]

Are you experiencing something that is causing you to consider a oil viscosity change? If you are getting good results with what you are using, why change? I have never changed the viscosity of the oil throughout the entire life cycle of any engine I have owned. From the 1974 Pontiac Catalina with a 400 small block that I finally got rid of at 267,000 miles, to the 2 semi trucks that I have taken to well over 1 million miles each on the same engine with NO rebuild or even a major engine repair.

Your engine is NOT high miles. I don't even consider a typical small block to reach the "high miles" category till over 150,000 miles in normal use. You are only 2/3 the way there! But if you are experiencing a significantly higher oil consumption, it might be an option, but doing that might just be masking a problem that will only get worse. A high mileage oil might help with some oil leakage from seals, but not if they are on their last leg. Pennzoil UP is a very solid oil. I would see no reason to go to anything else for quite a while.

 

[TexasToughTruck]

No, I'm not experiencing anything that would make me want to change oils except for the price! I thought I read somewhere that changing to a 10w-30 might be beneficial in higher mileage vehicles so I figure I would ask and get some feedback before I just changed without reason. Pennzoil UP is more expensive, and harder to find so I thought about switching to mobile one HM, they say its for over 75k miles. I'm just looking to prevent any problems and save a little money. Ive been doing some reading and it seems switching to 10w-30 may not be the best option if I don't see a need to but I figure i would switch to a high mileage synthetic as a preventative measure since they are all listed for vehicles over 75k and Pennzoil doesn't have a full synthetic HM, and they're more expensive. I am thinking about trying Mobile One HM 5w-30 and sticking with that.

 

[Cowpie]

No problem with going with a less expensive product. Look at the Pennzoil synthetic blends. There is really no need to run a full synthetic. The blends from Pennzoil are stellar products. Heck, even the Wally World Superrtech branded oil is a good oil. It has gotten good reviews from some of the folks over at the BITOG website, which is a lubrication specific website. You have a myriad of options. Look for sales. For the 5.3L I would at least recommend a blend, and there are a lot of good quality synthetic blends on the market. Go with what your gut and your wallet feels right about.

 

[TexasToughTruck]

Thanks for the input. I typically buy my oil from Pep Boys Website (even though I wont take my truck to their store) because they are always offering coupons and promos every couple of months and I usually get a good deal if I buy my oil in advance. Right now they have 25% off $50 or more. I just bought 6 qts Mobile 1 HM Synthetic and a mobile 1 oil filter for $58 w/ free shipping! Hard to beat that. I just check their website every couple of weeks for a promo and it usually pays off.

 

[RayVoy]

If your in Texas, using a 10W30 instead of a 5W30 will make no difference to your vehicle. The 5, 10 is the way the oil acts when in a cold engine, when the engine warms to operating temps, the oil acts like 30 weight oil.

Some of the advertised high mileage oils have additional additives, to help clean the engine. There are 2 schools on if this is good, sometimes it's best to leave a "dirty" engine alone.
But, you've been running synthetic oil, so your engine will not be "dirty" anyway.

The term "high mileage" may have too meanings, one is an oil for vehicles with high mileage, the other is where extended oil changes are wanted.

I didn't check the oil you where thinking of using, so I don't know which category it falls into.
If cost is a factor, maybe your changing the oil too early.

 

[Cowpie]

That's right. also some additional oil seal elastomers to keep seals fresh. Seems like if you got a good deal on the Mobil 1, it should be a good choice. Good deals are always a good thing!

 

[Pikey]

A heads up with the mobile 1 high mileage oil, per the mobile 1 website the high mileage is NOT recommended for extended idling intervals. I have no idea why or what constitutes "extended idle periods". I was running the mobile 1 high mileage in my 5.3l with over 170,000 on the clock until I read that on their site. In the winter my truck idles for 15-30 minutes to warm up before I take my son to school. (Again I don't know what is considered an extended idle period) Then I switched to the standard mobile 1. I have seen no difference in anything when I switched. (Not that I thought I would)


To answer rays question, the mobile one high mileage oil is for vehicles over 75,000 miles. They sell an "extended service" mobile 1 that is for OCI of 15,000 miles. But on my opinion the filter should still be changed at regular intervals. (I have no data to back that up, it just seems to make sense to me)

 

[phoebeisis]

I am a bit lazy
I switch my 1998 Suburban(bought 2007 with 195,000 $2950-now has 228,000 runs great) to Mobil 1 as soon as I bought it
Used 5w30-but after a couple of years I switched to 10w30 Mobil 1
I did it because It had "slightly lower oil pressure" 17 psi-than I "liked"
I'm in a HOT climate-New Orleans
In made no MPG difference that I could measure-and no real reason to switch- 17 psi IS PLENTY
But it also has an oil leak-probably at oil pan-plastic timing cover junction
so heavier weight will probably leak slower when the motor is off

Anyway I now use the extended service 15,000 mile oil-change it once a year-but a year is just 3500 miles

So it probably wouldn't hurt to go 10w30-but you don't need to-GM calls for 5w30-they probably know what they are doing

Yeah 97000 miles is NOTHING for a modern engine-they shouldn't break before 200,000 miles

 

[RayVoy]

To answer rays question, the mobile one high mileage oil is for vehicles over 75,000 miles. They sell an "extended service" mobile 1 that is for OCI of 15,000 miles.

Mike, I knew the difference, I just wanted to make sure the OP wasn't confusing the two terms.

 

[Pikey]

Mike, I knew the difference, I just wanted to make sure the OP wasn't confusing the two terms.

Oh ok! I kinda thought it was odd that you didn't. Sorry for the confusion.

 

[Cowpie]

Keep in mind, the only difference between a 0w30, 5w30, or 10w30 is the winter flow rating. That is the number in front of the "w". Has nothing to do with operating viscosity. They are all 30w oils. There are even some straight weight synthetic 30w oils that also qualify as a 10w30 simply because, even though they are a straight weight oil, they meet the winter flow rating to qualify as a 10w30. If someone is primarily in a warm climate, they will have no problem using a 10w30 oil.

GM has to cover all the bases of the average consumer, so they are going to recommend a 5w30. I have no problem with that. But I wouldn't even use that in Fairbanks, AK in the winter! I would use a 0w30. If I lived in TX or the Gulf Coast states, I would not hesitate to use a 10w30 if it was a better value than a 5w30. Just look for the sales.

 

[TimTom64b]

I've been around and around on oil weight... I believe I had inquired from GM on this answer also. They recommend not running anything other than the 5w30... Primarily due to tighter tolerances (main bearings etc) on newer engines.

 

[Cowpie]

That would indeed be an issue if we were debating 20w vs 30w vs 40w oils. But 0w30 vs 5w30 vs 10w30 differences are simply winter flow rating, not a viscosity difference. Many folks, including those who should know better since it is their business, have misconceptions about this. The American Petroleum Institute is very clear on this.

 

[Cowpie]

Let's take a look at the viscosity at 100c of a 0w30, 5w30, and 10w30 from a oil blender data sheet.....

The ow30, 5w30, 10w30 all have the same viscosity at 100c / 212F operating temperature. Only the cold flow crank start rating at engine startup is different. But notice something else.... the NOACK (burn off vaporization rate) is higher for the 5w30 and 0w30 than the 10w30. It is because more viscosity improvers are needed to make them flow at colder temps than the 10w30. And along with more VI, there is the increased possibility of oil shearing under extreme pressure. To get something, you have to sacrifice somewhere else. The assertions that a 0w30 or 5w30 is better than a 10w30 because of tighter engine tolerances are not grounded in reality. All of these oils have the same viscosity in engine operation. Only the cold flow is different. And GM's recommendation, while not invalid, is out of their motivation to cover all the extremes as best they can and overcome the low brain wave activity of many consumers. If they didn't make the recommendation they do, there would be instances of consumers dropping in a straight 30w oil, which would probably mess things up in cold temps.

 

[98BIGBLOCKBURB]

I would stay the viscosity that GM specifies in your owners manual unless they come out with an update based on solid research.

 

[Cowpie]

As I stated, I did for the most part. They recommend a 30w oil. And that is what I use. We just differ on the cold winter flow rate, but I don't live in Duluth, MN in the winter.

 

[Dan Alpert]

Hello,
I know this is a post from a couple of years ago, but I had to respond in case anyone else is considering a similar issue.
Here's the beef on changing oil viscosity in these engines.
First off, in 2011 GM changed the oil requirement so that the oil used in these engines is REQUIRED to have the Dexos1 rating on them. At this time only synthetic and certain synthetic blend oils, and only in the 5W30 and in extremely cold temps, 0W30 weight oils are Dexos1 approved. The bottle HAS to say Dexos1 approved on the bottle or it does not meet this requirement. If there is any usable warranty on the engine, and it goes out, GM will not honor the manufacturers warranty if oil not having the Dexos1 rating is used.
At this time, Mobil 1 HM 5W30 does not have the Dexos1 rating in it, but, for instance, Valvoline Synthetic HM 5W30 does. I'm not sure exactly why Mobil does not have the Dexos1 rating on this oil, but maybe in the future they will add that. I have searched on the Mobil 1 website but did not find any reason why the HM 5W30 doesn't have the rating when the rest of the Mobil 1 5W30 and the 0W30 Synthetic oil's do. Even Mobil Super Synthetic 5W30 has the Dexos1 rating and it's in the conventional Mobil line. For that matter, Castrol's new synthetic blend oil Magnatec 5W30 has the rating as well, and that's based on it's conventional GTX oil.
So any oil used in any oil change in 2011 to 2013 engines must be 5W30 or 0W30 with Dexos1. 2014 and later 5.3L engines also must have the Dexos1 rating and MUST be 0W20 oil. GM did increase these engines to 8 quarts from 6 quarts oil fill. Again, this is just for the 5.3L engine and maybe 1 other like the 4.8L engine. I believe the 6.0 or 6.2L engines are still 5W30.
Prior to 2011 back to 1999 when these series engines came into production, the recommended oil weight is 5W30 for year around use, but in any temp above 0 degrees, 10W30 may be used. The 2008 to 2010 engines highly recommend staying with 5W30 but 10W30 isn't prohibited.
Using High Mileage oil in these engines is owners choice and I only recommend using it when an oil usage or leaking issues are present. Otherwise, keep using what you are currently using as long as it is the proper weight and viscosity your engine requires. That's for any engine. Using High Mileage oil in those situations may not completely correct the issue, but should help slow down and MAY correct it. However, the situation may be bad enough that only an engine rebuild may completely correct the burning or leaking issue.
Short story, your mileage may vary.

 

[Truck Guy]

I have a 2000 Silverado 1500 and I am in a similar situation as yours. The factory recommendation for oil is different from what you can find on different websites and forums. Auctionsdirectusa recommends 0W-20 while thecarslab recommends 5W-30. Little confused right there. But for now I assume that 5W-30 is good for high mileage and 0W-20 for low.