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oil what brands and type

5K views 26 replies 17 participants last post by  krausee 
#1 ·
I have 99 2500 hd 6.0. 140000 mi want to change over to full synthetic. Want your opinions please good or bad. Also what brand i usally mobile one or Valvoline.
 
#2 ·
With that many miles on your truck I would stick with the regular oil. In many cases, switching conventional oil to full synthetic on a high-mileage vehicle can have detrimental effects on the engine. Synthetics have a thinner viscosity and could easily damage gaskets and other delicate parts of your engine when transitioning from conventional oil, which has a thicker viscosity.
 
#3 ·
There will be lots of opinions on this subject.It is my understanding that there are no detrimental effects when switching from conventional to synthetic oil no matter how many miles you have on your truck.The benefits of synthetic oils are longer oil change intervals and better cold starts.Some more expensive brands may have a better additive package as well.I use full synthetic oil in all my vehicles and change oil/filter every 5000 miles.It may be possible to go longer if the vehicle sees light duty.You can get Mobil1 farly cheap at Wally World or Costco.
 
#5 ·
I have heard that synthetic oil can leak through areas where conventional cannot. The molecules are actually alot smaller. That being said, I switched my old RSX to synthetic at 150k and had no problems, and those motors are basically 0 tolerance/interference fit. IMHO Synthetic oil is better in general, however if conventional got you 140k+ why switch now? Just put some high mileage name brand in it and roll.
 
#6 ·
I have used only Castrol GTX oil in my vehicles over the last 30+ years. Never had an engine problem with any of them, but I don't beat on my equipment either. I've run a diesel for about 10 years on Mobil1 Delvac synthetic with good results too.

When it comes time for an oil change in my Sierra 5.3 (recently bought with 9000 miles on it), I plan to put Mobil1 in it.
 
#7 ·
There is lots of misinformation and myths about synthetic oils.

The molecules are not smaller, they are all all the same size, its just that non-synthetic oils have molecules of varying sizes. Molecules all the same size mean less friction and less heat.

Synthetic oils do not necessarily have thinner viscosities then identical mineral oil . Oil viscosity of engine oil has to fall into a range, so all oils labeled 5W-30 all fall into the same range.

Leaks occur because of defective seals and almost always exist prior to using synthetic oil.

My CTS came with synthetic oil and requires synthetic oil. Putting non-synthetic oil could cause engine damage so say the owners manual.

PS-I have been using synthetic oil for a very long time.

Should you put synthetic oil in an engine over 100,000 running on mineral oil? You can if the engine is in very good mechanical condition. Synthetic oil is not going to cure problems. But you have to weigh the cost effectiveness of doing so.
 
#9 ·
Like I said, lots of myths about synthetic oil.

Remember though, like tires and beer, not all synthetic oils are created equal. With oil the old saying is true, you get what you pay for. If its cheap, its cheap for a reason as they likely to have cut corners to be able to sell it at that price. Also avoid generic/store brand synthetic oils unless you like taking chances. Recent industry random testing has found many store brands to be not as labeled, in other words a crap shoot as to what you really are getting inside the bottle.
 
#11 ·
But Mobile One Extended Performance Full Synthetic, Pennzoil Platinum, Amsoil XL about the three best oils that you can use for the truck. In order to get the best performance for your truck send your oil into Black Stone Labs and get your UOA (Used Oil Analysis). But in order to do this you have to run the oil you want to test for at least two oil changes. After reading a lot of threads on Bobistheoilguy.com the oil that had the best UOA's was Amsoil XL in GM trucks. But it was also said that any Name brand synthetic 5w-30 with a K&N filter or Mobil 1 filter and following the Oil Life Monitor will still yield you a very long lasting Gm truck. So really it all comes down to personal preference.
 
#12 ·
I am using the AMSOIL SSO 0W-30 in my my 2009 Cadillac CTS4 and also in my 2010 GMC Sierra. I change oil only once a year but between both vehicles. I only put about 15,000 miles more or less annually. The Sierra I also use the AMSOIL oil and air filters but they CTS4 does not have any available so I use AC Delco. I also am running the gear lubes in both the car and the truck.

PS -- I have been an AMSOIL Dealer for more than 20 yrs.....................
 
#14 ·
I have had at least a dozen oil analysis done between my Duramax and three different Vettes. I used several synthetics and two regular dino oils in my Duramax. I ran them all a minimum 5K miles. I used several name brand filters. Everyone came back with very good results. I used Pennzoil Platinum with AC Delco filters in my 93 & 04 and got excellent reports. I just sent in a sample yesterday from my 08 Vette. It has 5K on Mobil 1 with an AC filter. I expect the same results. All these engines put more load on the oil than the 5.3 in my 1500. Later! Frank
 
#15 ·
I personally use synthetic in all of my vehicles (cars and trucks). But in reality as I told a friend (and I'm not a mechanic by the way) as long as its clean and filled to the appropriate level, it shouldn't really matter. But I tend to use Mobil 1 within the first 3,000 miles of any vehicle (and after break-in periods).

I have heard that it's not beneficial to transition to a synthetic blend on a higher-mileage vehicle (I'm thinking over 75k) and especially not with the miles you have at 140k. My friend is experiencing this with his truck (a 2001 Ford Ranger with 185k on it). He used Mobil 1 once or twice and then realized that it really didn't matter in his truck because the engine was leaking and burning oil (not horrid amounts, but some) anyway, and that it really wasn't worth 3x the price of generic conventional oils. If it was my truck, I'd just stick with what you were doing--conventional oils. I'm not a mechanic, but have talked to many on this subject--with varying opinions of course. It ultimately comes down to whatever you want and how much you want to spend. At 140k, I don't think it's going to matter either way.
 
#16 ·
Schaeffer makes an outstanding oil and lube lineup. They have been at this longer than anyone else in America... since 1839. Here is a link to a video of an engine out of an Econoline van that had 1 million miles on it without being opened up for a major repair......



They are advertising their 9003D 5w30 full synthetic as now dexos approved. Not on the web list yet, but that list was updated last May. I have used their products in some of my vehicles and equipment for a few years now. I buy in bulk, so I can get pricing that beats even Wally World pricing on oils. Their regular retail pricing is not too bad and competes quite favorably with other boutique oil pricing.

www.schaefferoil.com
 
#17 ·
Frank B said:
I have had at least a dozen oil analysis done between my Duramax and three different Vettes. I used several synthetics and two regular dino oils in my Duramax. I ran them all a minimum 5K miles. I used several name brand filters. Everyone came back with very good results. I used Pennzoil Platinum with AC Delco filters in my 93 & 04 and got excellent reports. I just sent in a sample yesterday from my 08 Vette. It has 5K on Mobil 1 with an AC filter. I expect the same results. All these engines put more load on the oil than the 5.3 in my 1500. Later! Frank
This poster has proven that since he has run both conventional and synthetic, and the UOAs came back good on all oils, that today's conventional oils are very good. Unless your going to see temps below -25 degrees (when conventional does have issues) I wouldn't switch at your mileage reading.
 
#18 ·
sirhawkeye said:
I have heard that it's not beneficial to transition to a synthetic blend on a higher-mileage vehicle (I'm thinking over 75k) and especially not with the miles you have at 140k. My friend is experiencing this with his truck (a 2001 Ford Ranger with 185k on it). He used Mobil 1 once or twice and then realized that it really didn't matter in his truck because the engine was leaking and burning oil (not horrid amounts, but some) anyway, and that it really wasn't worth 3x the price of generic conventional oils. If it was my truck, I'd just stick with what you were doing--conventional oils. I'm not a mechanic, but have talked to many on this subject--with varying opinions of course. It ultimately comes down to whatever you want and how much you want to spend. At 140k, I don't think it's going to matter either way.
I converted a Dodge to Mobil 1 High Mileage at over a 100k. It worked great! The leaking slowed (not stopped, but acceptable) after the 2nd oil change. I am a fan of high mileage oils in the higher mileage vehicles. That said, I do not consider a GM truck engine to be high miles at 100k. Considering mine was still throwing copper at 20k (evidence of still breaking in) on the UOA's, I don't see why 100k is "high".
 
#19 ·
I went to amsoil full synthetic at 210k... before that I used castrol gtx highmileage which is a synthblend..... I have not had any oil leaks and I run 10k change intervals in my truck on amsoil and at a change im less than 1/4th a quart low.

sent from my Verizon Wireless Galaxy SIII
 
#20 ·
CKNSLS said:
Frank B said:
I have had at least a dozen oil analysis done between my Duramax and three different Vettes. I used several synthetics and two regular dino oils in my Duramax. I ran them all a minimum 5K miles. I used several name brand filters. Everyone came back with very good results. I used Pennzoil Platinum with AC Delco filters in my 93 & 04 and got excellent reports. I just sent in a sample yesterday from my 08 Vette. It has 5K on Mobil 1 with an AC filter. I expect the same results. All these engines put more load on the oil than the 5.3 in my 1500. Later! Frank
This poster has proven that since he has run both conventional and synthetic, and the UOAs came back good on all oils, that today's conventional oils are very good. Unless your going to see temps below -25 degrees (when conventional does have issues) I wouldn't switch at your mileage reading.
I would throw a proviso in on that comment. The fact of whether the oil is a synthetic is only part of the equation. The additive package makes up roughly 40% of any engine oil, and the synthetics usually have a more robust additive package to compliment the synthetic. Better detergents and other characteristics can be as much a determining factor as whether the oil is synthetic or not. And you do not have to get below -25F before conventionals have issues. That is typically the pour point area of most conventionals. Even before the pour point cold limit, the oil is thickening up enough to be an issue. Once you get into sub zero territory, the ability for a conventional to get up to the top of the engine at cold start up and lubricate can become an issue, depending on port size and such. A full synthetic will get up to the top side quicker on start up than a conventional in sub zero temps. That is, unless you are using an oil pan heater, in which case it is a non issue.

And the 5000 mile testing interval that is being commented on, just about any oil will do great at that interval. I regularly go out to 20,000 mile oil change intervals on my current diesel. Would go a tad bit longer, but biodiesel fuel dilution is becoming more of an issue now that all the major fuel stops are increasing levels of biodiesel blends. I have never in the last 2 decades changed oil in a diesel less than 10,000 miles, including the 2.8L diesel in a 2006 Jeep Liberty we had, and one engine even got oil changes at 30,000 mile intervals and went to over 1.4 million miles without ever being opened up for a major repair. My gassers usually get oil changes between 6000 and 7000, only because that is my comfort zone with them since they live on a pretty study diet of E85. They could go longer.
 
#21 ·
With all that said I think it would be a good idea to do an engine flush prior to going to synthetic. Any brand oil is good but whatever you go with stick with it I was told years ago (by a mechanic) that don`t change because different oils have different additives and makes a differance.
 
#22 ·
^^^
One could argue that using different additive packages is a good thing, since it changes the cleaning effectiveness, wear characteristics, etc. Kind of like averaging out all different properties. That's just my simple reasoning, not fact....and not something I follow. My Sierra has had a steady diet of Amsoil since about 6,000 miles.
Also, engine flushing is a hot topic as well. I have always done a Sea Foam flush at each OCI. Given the propensity for carbon build up in the AFM engines, it seems like a good thing. Some may argue I am causing additional wear and that if I don't get it drained 100$%, I am diluting the new oil. Possibly, but so far it's worked well for me.
 
#24 ·
Working on saving the $$$ to do just that. Or maybe from Santa this year!!!???
 
#26 ·
Never heard of that. But WOW! Wow for a lot of reasons.
First, who buys oil from a party or discount store? :roll:
And, why would a company want to ruin their reputation (if they had one) by doing this? Obviously, this company is 100% DONE.

Mike, people that were buying this CRAP probably won't be easily converted to a premium synthetic like Amsoil, huh? :lol:
 
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