xcnick38

its time for me to get my truck serviced, oil change, transmission flushed/changed, transfercase changed, and front + rear differentials changed... im considering going to all synthetic oils, in everything... im wondering if it is worth it to spend the extra $$$ on synthetic as compared to conventional oil. i wanna run synthetic in differentials, transfer case, transmission, and engine.

any tips? suggestions? im leaning towards the amsoil side right now? is there anything better out there? my current mods are AFE cold air intake, muffler delete, boost, trans and egt gauges, 2.5" leveling kit, 18" rockstars, 305/60-18 mickey thompson atzs... i'll have a smarty jr. within the next month or so...

thanks
nick

92'1stGen

Spending the extra money on synthetic engine oil IMO is a good investment. Which ever oil brand you go with, make sure that at the least it is CI-4+ rated. CI-4+ oil is hard to find these days and there is only one synthetic oil that comes to mind that is rated that: Amsoil 15-40 HD Diesel and Marine oil. Some may say, "o it's a 15w-40 it won't be good in cold weather". Wrong, the pour point of the Amsoil 15w-40 is -44F compared to -51F of there 5w-40 diesel oil, it'll be just fine. I'd also look into a bypass filter setup as well, it'll really allow you to get the most out of your synthetic oil.

In the transmission I wouldn't waste the money on Amsoil's ATF, not because it's bad, but because it's a waste of money. Change the fluid in the pan every 20k - 25k miles and refill with Valvoline or Mopar ATF-4, and everything will be just fine. It's better to change often and replace with new regularly rather than waiting to do a complete flush when the fluid has gone bad.

In the transfer case and diffs synthetic can be a benefit, but for the transfer case at least, I just run the Valvoline or Mopar brand ATF-4 in there too since that's what it calls for. In the diffs I would run a synthetic. Rear diffs especially, can see a lot of heat, particularly in the middle of the summer when towing.

.boB

It depends on the intended use. There are two big advantages to synthetic oils, motor oil specifically and other oils in general.

1. Increased heat tolerance. Engine oil is heated by rpm's, and tends to follow coolant temps. Diesels don't see that many rpm's. If you have trouble keeping the engine cool, then use synthetic. It won't be any cooler, but the oil can withstand the heat better.

2. Longevity. You can easily go 8-10K miles on a good synthetic; again, depending on use. If you drive a lot of miles every year, you could potentially cut your changes in half. Not much dollar savings, but maybe time savings.

Other than that, you'll probably never notice the differance between standard and synthetic.

Also, keep in mind that AFAIK there are only 4 true synthetic oils on the market - RP, Redline, Amsoil, and I can't remember the 4th. These oils are PAO base stock oils.

The rest of the "synthetics" are really highly processed dino oils. That's OK, there's nothing wrong with them, and they're considerably cheaper than true synthetics. But they don't handle abuse like PAO's do. I wouldn't heistate to use RP for 10K miles, but I wouldn't use M1, QS, or Penzoil that long.

Sinbadd

I believe that the ATF + 4 is synthetic.

Swayse

Last few oil changes I went with Royal Purple, I had planned on running it 10,000 miles, but when the truck gets to around 5,000 miles the oil is so black so I change it early. I just changed it a few days ago, and this time I went with a good CI4 oil from my local Case IH house. It's only half the price of RP, but I'm just gonna stick with my 5,000 mile oil changes.

Trans, transfer case, and power steering I go with ATF+4 every 30,000 miles. Axles I changed at 30,000 miles with RP, and I'll change it every 100,000 after that.

bansh-eman

I run synth in everything but the motor.

I like Valvoline products. ATF+4 for the Tranny, T-Case, and power steering, DOT 4 Synth brake fluid, 75w90 synth gear oil for front and rear diffs.

For motor oil I like running conventional. I use Rotella T. I just put Mobile Delvac in this change because they had a great deal on it. We change the oil often enough that you shouldn't need synth unless your doing sled pulls or something to really heat the motor up.

I don't buy into the Amsoil hype. I beleive the biggest reaso everyone love it so much is because anyone can become a "dealer" and this has helped them tomarket the product.

There are only a VERY small amount of oil manufactures in the US, and Amsoil is not one of them. Every one buys thier oils from them and add thier own little touch to call it unique.

nelrod

I would take Banshee's advice. Synthetic in everything but crankcase. And I too believe the ATF from Mopar is sythetic. If you plan on putting a bypass filter on and going for extended oil changes, and using UOA's, then I would use synthetic. If you want read a lot more about it go to www.bobistheoilguy.com

soulezoo

Schaeffer's is another "true" synthetic and a fine oil. I run it in my diffs and it's been great.

I used to run it in the crankcase as well with good results... stopped only because it can be hard to get. I am running Amsoil now with a bypass setup.

IMO, the best reason to now use good synthetics or the so called "boutique" oils is because the newer oils are so low in things that are very important in preventing wear, like ZDDP, and the neutraliztion of acids and now the newer CJ-4 oils are also found to not keep soot in suspension as well too. Schaeffer's, Amsoil, Redline, RP all still have good amounts of good stuff without having to resort to additives.

Amsoil in the tranny and x-fer case. Not because I am going to exclaim it is so much better... but it is of the best quality and I've seen excellent results; the main reason was it cost me the same as Mopar ATF+4 at the time. Mopar ATF+4 is a synthetic fluid and is good stuff.

Nelrod is correct in referring you to Bob's the oil guy...