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ORIGINAL: melat70
I have a 2002, 2500HD, with the 8.1, and 85K miles on it, and have always ran Quaker State 10W30, and have had good service from it. I always do my own Maint. and change religeously 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???
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 guess to the old wives tale about not swapping brands of oil on vehicles. That is related to conventional 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 used many brands, had a crank bearing go on me. Was it the oil? Don;t know but the engine only had about 10K on it after I rebuilt it and this is the only engine 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 safe longer 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.
