I read about the synthetic switching process...I think on the Amsoil website. They recommend using an engine flush to remove a lot of the old gunkcaused bythe conventional oil. But it says it's not totally necessary, as this will happen over time anyway when you switch. I will be switching to synthetic on this next oil change, and I am anxious to see if I have any difference, too. I am still deciding whether I want to run the Mobil HM or just the Clean 5000. I didn't see anywhere on the jug of the HM where it said anything about protection lengths, did you? I know the Clean 5000 said 5K miles/6 months, but I wonder if the HM synthetic is also meant to protect that long.

 

Im not sure about the protection lengths. I did some internet reading on synthetics and they say the reason you need to change the dino oil every 3000 is due to impurities in the oil that they dont get out when refined. They say syn oil has no impurities and thats the reason you can run it longer as the protection does not break down as quick. They claim you can run 10,000 plus miles before changing. Im not comfortable doing that with out sending an oil sample in for testing like some fleet companies do. So I figure i will just run it for 5,000 and pay the extra money for the protection and hope the engine will last longer!!

 

I also heard that the engine flush chemicals actually cause more wear to the engine, but I dont have any evidence to back that up either. Just one of the articles I read when researching the synthetics.

 

I would be very surprised that there are many impurities remaining after today's refining processes. Depending on regular driving conditions, a car running on Dino oil can go almost 9,000 miles before the dino oil starts losing viscosity. That is the #1 issue with dino oil. Petroleum engineers have been working on that for DECADES in order to increase engine tolerances and lifespans. Engines build in the last 20 years have much closer tolerances that engines from the 1960's and earlier. Also, the oil filter is there to pick up impurities. If you wanted, you could change the oil filter every 3,000 miles and top off the oil as needed running dino oil and go almost 12,000 before performing a fresh drain and refill. 3,000 is an old school method (most) mechanics and dealerships continue to abide by although it is a horribly outdated concept.

 

Makes them and the oil companies a lot more money than otherwise, too.

 

My engine has just about 120k miles on it, so i'm interested as to what's the best syn. oil. I just put some pennzoil 10w30 last oil change and it was pretty clean when i added a qt a couple weeks ago. But I think I have the plenum leak, not positive though. Anyway, I wonder about the high mileage syn. oil and if it would be a good try. Let me know what you do!

 

Well, I definitely like the high mileage oil, because it usually has additives in it that help older engine seals stay fresher. I am changing my oil this weekend, and I am going to switch to full synthetic...Mobil 1. There is no clear cut answer on which synthetic oil is the best one. Amsoil and Royal Purple are among the best, as is Mobil 1, in my opinion. The only full synthetics that I have found with a high mileage version are Valvoline and Mobil 1...there are more I'm sure. Going full synthetic will be a good move, but I don't know that going with high mileage oilis a have to...more of your choice. I will more than likely be running Mobil 1 Clean 5000 10W30 with a Mobil 1 filter, changing every 5K/6 months. For the price, I don't think you can beat it...

 

I've had that Royal Purple itch. Either way, with my transmission fixed and everything goin on personally, I won't have money for anything for a couple weeks. Not even an oil change.

 

Well, you can plan about $50 for a change with RP and a good filter...not bad for a 6-8 month change interval... Honestly, for the money, I don't think you can beat Mobil 1...

 

i use mobil clean 5000 with st oil filter or a mopar oil filter , cant beat the price at 2.22 qt....