melat70

I have a 2002, 2500HD, with the 8.1, and85K miles on it, and have always ran Quaker State 10W30, and have had good service from it. I always do my own Maint. and changereligeously at 3K miles.I have been condidering changing to a quality synthetic, I have always heard that you should not change brands/type of oil in the middle of an engines life. Does anybody have any data or experience in doing this. Is the synthetic oil worth the added cost? What are the benefits in using synthetic, and what brand of synthetic would be a good choice???

NHSilverado

As long as you have done "religious 3K oil changes" you will probably be okay swapping over at 85K. You have to be careful swapping to a synthetic oil for the 1st time on high mileage vehicles. As long as you do not have any oil leaks or seepage issues now( ie; valve covers, intake, rear main, etc... ), and as long as you do not burn more than 1 qt every 3K or so, you should be fine swapping over. If however, you have either one, or both, of those issues now then take care of them 1st. Otherwise they will worsen with synthetic oil.

Also, with 85K run solely on conventional oil you will have some internal build up and sludge. Just will even with those 3K OC's. Just won't be really bad. You are best off to do anther quick OC( like 2500 miles or so )after the initial swap over. The detergents in synthetic are vastly superior to those in conventional oil and they are going to dissovle any and all "gunk" in there( actually this is what leads to the problems above - the detergents remove the build up thus exposing areas that the build up were sealing off which makes them start to leak or leak worse).

Don't run an extended oil change interval( like 10K+ - I wouldn't even go 5K on the 1st one)the very 1st change with it. If you do then you run the risk of clogging the filter and/or oil pickup screen with all that crud in the oil. Do a quick OC and check to see how bad the filter is and the oil coming out. You may even want to do another 2500 mile OC. After 1 or 2 you can start running whatever OCI you wish. The 1 or 2 quick ones are just a precaution, BUT, IMO, a necessary one..

There is some truth I guessto the old wives tale about not swapping brands of oil on vehicles. Thatis related toconventional oils though and the specific minerals and such in them based on where the crude came from( ie; PA vs TX crude base stock ). Supposedly it can lead to some issues if you swap brands all the time. Is it true? I don't know 100% for sure but it was how I was taught and thus I believe it to be so. I have never done a lot of brand swapping on conventional oil as a result.

The one vehicle I did use whatever name brand oil was cheaper( had an oil leak I couldn't afford to fix right away), and thus I usedmany brands, hada crank bearing go on me. Was it the oil? Don;t know but the engineonly had about 10K on it after I rebuilt it and this is the onlyengine I ever did that went south.Back when I worked in the auto field a LOT of mechanics that knew their stuff told me this as did a few oil rep's. Your call if you believe the "myth". Not a problem going to synthetic however. You can even go back to QS if you feel synthetic is not for you and be fine.

Yes, IMO, synthetic oil is definitely worth the cost. Vastly superior product vs any conventional oil. Your engine will run cooler and there will be less wear( reduces friction ). Synthetic retains it's viscosity to a much lower temp than conventional oil so if you live in a colder northern climate it will flow easier in the AM and allow for more cold start protection. Synthetic also clings to the metal surfaces whereas conventional drains off so again, at cold start, it protects better. Also, synthetic does not break down as easy under high heat and extreme load as does conventional so it is also a superior product for the South's warmer climate.

I personally use and suggest Royal Purple( http://www.royalpurple.com ). Great product and excellent company to deal with. Should run you around $6.50 +/- p/qt. If that is just too much for you then a cheaper decent synthetic oil is Penzoil Platinum( $4-$5 +/- ). Not as good as RP but very good and better than Mobil 1 for approx the same cost. Quaker States Q-Power is decent synthetic for the price although it is not a premium level synthetic. If you like QS though it might be a good, more affordable, option for you.

One thing to keep in mind. If you wiill run extended OCI's( ie; anything over approx 6-7K )the filter needs to be swapped by 5K. You might get 10K, 15K, or even 20K plus out of the oil( only way to really be safelonger than about 10K is to have the oil tested - there are labs that do it )but the filter can not go that long. You need to swap the filter and top off the oil between 4-5K when running extended OCI's.

Hope this helps.

melat70

NHSILVERADO
Well I certainly appreciate the info, and all the detailed data. You have convinced me to go to synthetic. Everything you have said really makes logical sense. I would not have thought about the early changes to clean out the sludge using synthetics. I have not noticed any leaks up to this point so hopefully the synthetics won't cause any,but if there are any leaks that develope, I won't be suprised, and will be able to deal with them. Are you a Royal Purple sales person? I will certainlyexplore using it. I have always tried to maintain on a rigid schedule, and using quality products, and I believe it has paid off. Thank You for everything.
Mel

NHSilverado

No, I am not a Royal Purple employee of any kind. No ties to the company at all. Just a loyal and satisfied user.

melat70

NHSILVERADO
I hope you were not offended by my comment. I was only joking because you are so enthused about RP. I have used RP in my differential and am very satisfied with it. Again Thank You for the through info.
Mel

NHSilverado

Nope, no offense taken. Unfortunately, there are some folks that take this stuff way too serious and get offended if you don't like "their brand". If people start thinking I work for RP it is a titleI wont be able to shake.

Every time I post about RP being better than XYZ they will start saying I work for RP and I am biased and such. Just wanted to make it known I am NOT affiliated with that company in ANY way. Just a loyal customer.

I actually had that happen to me on a duck hunting site I used to belong to. I was very vocal about liking a certain boat blind. Someone one day decided I must work for them and posted something similar to what you did. From that day on I was labeled an employee of that company and it caused me no end of grief. Even the owner of that company posting up I did not work for them and was just a customer didn't solve it. Another boat blind company threatened me and the company I praised with a law suit claiming I worked for the other guy and was trying to black ball them. It was NUTS!

People actually don't like it when employees of companies answer these types of questions( that includes me - I want answers from actual users not paid product pimps ). I just don't want people thinking I am an undisclosed employee of RP. Just want it clear.

No problem and best of luck to you.

Waboom!!

Amsoil

03blackburb

If you have had the truck since new and have been doing 3K changes with dino, WHY are you wanting to change to synthetic at this time? Are your looking at going to extended drain intervals? My thoughts on this is if you are going to continue doing less than 10K changes then stay with dino and save the additional cost for synthetic and use it for fuel.

melat70

Hi 03blackburb
I am interested in grtting the best lubrication possible and also not having to change my oil so often. However the down side of that thought is that I will still have to get greasie while doing chasis lube every 3K miles. You do have a point to consider.
Thanks for your thoughts
Mel

03blackburb

First, I use the OLM for calculating when to do service. In mu suburban, starting at 3K, I did a complete oil drain, including filter and fill with M1 5W30 Full Synthetic and reset the OLM. The next time the OLM came on, about 5K to 7K miles, I do a filter chamge and top off the crank case with about 1 quart of fresh M1. This cycle continues until I hit about 28K or 4 cycles of the OLM. Then it is time to do a complete drain and start over. In over 50K I have only done 3 complete drains, but about 7 filter changes. Yes, I have had the oil anaylised and it is testing out fine. Probaly could go another OLM cycle, which I might do next time. Visually the oil os still very clean looking and not very dark or black.
My '94 vette is a different story. It gets a complete drain and change everytime the OLM comes on. Between the heat and the extreme temps it is ready for a drain. But that is a different story.