Synthetic Oil vs. Real Oil

:idea: In switching to Synthetic (In my case at 10,000 miles coming up) is there a problem mixing Synthetic with the dino oil remaining in the ICE, that didn't fully drain?

 

http://www.bestsyntheticoil.com/amsoil/flush.shtml is a prospect...

 

In my opinion (and its just that) Amsoil is perpetuating an old wives tale that in the end hurts them as much as anyone else. I've heard numerous claims of dyno packing up in motors and syn cleaning it out and causing issue. Never seen anyone claim this would happen as low as 10k. Most have said not to put it in old motors as you may end up with leaks.

Nothing is going to build up in 10k. And if the detergents in the oil circulate the old "chunks", what on earth is the flush going to do?

If you were really concerned, you could swap out the first syn fill early.
I've swapped cars over to syn at various mileage. Never had a problem.

YMMV

 

As far as disposing of the used oil, when I was living in SLC I would always buy my Mobil 1 at Autozone. I would then return to the same store with my change pan full of used oil and they'd take me into the back room where the used oil drum was.

I had to fill in a logbook with my name, address, phone number, quantity and type of oil. No charge for that. Not sure how it's done now.

In Canada, I just dump it on the ground. I'm kidding! The local landfill has a used oil collection system, you put the used oil in the giant tank and they take your name and address.

 

Maybe after 60,000 miles of hard use. I rather doubt a properly maintained motor with 30,000 miles on it will present any problems.

It's true a synthetic oil has much higher levels of detergents, as the more stable oil structure allows this. If you still have a concern, maybe change the oil after 2,000-3,000 miles, then go to a normal 5,000 mile oil change routine.

BTW: if you read the fine print in Amsoil's extended oil change claims: "if supported by a used oil analysis program." Otherwise they want you to follow the manufacturer recommended oil change. So I use Mobil 1, it's half the price and IMHO just as "good" as Amsoil.

That has more to do with poor quality seals that will leak anyway. And if the motor has any RTV in it, then it *will* leak like crazy as the esters in synthetic oils will dissolve the RTV.

Much like how if you want to use synthetic gear oil in a rear differential, you have to take the rear cover off and scrape off all the RTV. Then you reassemble with a gasket instead of RTV. Otherwise the esters will dissolve the RTV seal and you'll have a puddle of gear oil in your garage.

Yeah, been there and done that! :cussing:

 

Some parts stores will take oil off your hands. They have a bin or tank they take it in. If they charge you to do that avoid it unless it is your only option. The oil you give up has a scrap value and eventually finds its way into some kind of reprocessing for another use. Don't ask me what, maybe that topic is worth a new thread.

Some counties have an oil recycling program and have deposit tanks located in convenient places such as at parts stores or garbage dumps or recycling centers that take other items, like glass, paper and aluminum.

Lube joints may or may not just take your oil off your hands. Depending on your locality, some places have to pay a hazardous waste tax or fee, and on top of that they usually have to have a company come by and take all their used oil off their hands on a frequent basis. That means that they end up paying to have your oil taken away. Again, some may charge you to do that because you are using their disposal service, or some may just let you do it without thinking much about it.

 

Thanks for all the input. Just got my Millenium Silver 05 pkg 6 Prius today, and have already been checking it over.

Upgraded to Michelin HydroEdge tires, and found cooled 32 psi in each, so I increased it to 37/39 rear/front. Drove before and after, and honestly feel like it rides great after increasing the psi.

Engine oil overfilled by one quarter inch...guessing from the factory. Would anyone recommend doing something about this? Take to dealer and ask them to drain a little out? Replace oil with Mobil 1 now and start fresh?

Also, took the car for a test drive, and it takes 61-62 mph on the speedometer to go exactly a mile in one minute, so it appears to be slightly overstating my speed. There is a minimal difference in the stock Goodyear Integrity vs the Michelin HydroEdge tires in revolutions per mile, 855 vs 856 respectively, and not sure that small amount is enough to account for the difference? Is this something that can be calibrated at the dealership?

Any input appreciated.

Daisy

 

Though my new 2005 Prius is not due for an oil change yet (only have about 900 miles on iit so far), I have used synthetic oil in a 1993 Mustang Cobra since it was purchased new. That car has 102,000 miles on the clock and runs very strong. I have run that car very hard at times, and I believe that the synthetic oil is an added layer of engine protection in a high-performance car.
My last commuter car was a 1991 Pontiac Grand Am with a "Quad 4" 4-cylinder engine. I used synthetic oils in it since purchase, and just retired the car when I bought my new Prius. The Grand Am went 168,000 miles with no major repairs, and the engine is still running strong (the rest of the car looks like hell, though).
I will also use the synthetic in my Prius. I plan to keep my Prius for a long time, and I have good results in my other cars to cause me to believe that the synthetic oil is a better lubricant and reduces engine wear. If I get one or two MPG out of the deal as well, all the better.

 

No. Syn oil and dino oil are completely miscible. This idea that the syn oil's higher detergent levels will dissolve sludge / goo / chunks is not a concern in a well-maintained car. Now if a car has been seriously neglected and has a LOT of miles on the clock, it may be a different story.

 

I went back to the dealership today, and they agreed to drain out some of the excess oil. After 5 minutes, the service technician declared that the oil was exactly on the maximum fill mark, and no oil drain was needed.

I drove home, and checked it again myself, and indeed, it was again between one eight and one fourth of an inch overfilled. My Prius was warm when tested, sitting about 5 minutes on level pavement. The oil is so clear, that one must have good vision to see the mark, but it was definitely overfilled.

No need to bother them anymore so as not to burn bridges, but I will either drain it myself or go ahead and make the change to synthetic oil now...ordered a fumoto valve to make future changes easier.

Reading on Mobil's website states one can switch to synthetic oil at any time...no break in period is needed, so I just may go ahead and do that when it is convenient, maybe this weekend.

Only have 125 miles on it so far, and am averaging 45.5 mpg. This may be overestimated, though, because my Prius thinks it is going faster than it really is...takes 62mph to go a mile in a minute in mine. Wonder how common this is? The Toyota dealership said it was within the expected margin of error.

Next to make up my mind on oil filters. Probably will just drain the current Toyota filter, and replace it since only has few miles on it. Next time, have to decide whether to go with a Mobil high quality filter, Purolator, or Toyota. Any suggestions?

Daisy

 

Daisy,

We're using the Mobil-1 oil filters in both of our Priuses, and they work fine. A little pricey, but all in all a nice filter.

If you're using Mobil-1, remember to call up the Mobil-1 hotline and request some "only use Mobil-1" stickers, lest your dealer dump in some dino oil by mistake.

Don

 

Regarding oil, as has been documented by Toyota and several powertrain engineers, you should wait until your first oil change at 5000 miles before changing to synthetic. This will allow for a more efficient breakin and improved performance in the short term (allows for normal part wear during breakin to occur as intended).

Regarding oil filters, there is a website somewhere that has detailed teardowns and data of oil filters (link anyone?). The Purolator Pure One is top rated. The Mobil 1 filters were found to be pricey while not offering any additional benefits. Save your money.

 

Responding to my own post for those interested....

Link to good site with oil filter information is:

http://minimopar.knizefamily.net/oilfilters.html

To support my previous statement regarding Pure One filters, while I respect the author's opinion with respect to flow concerns, without data it is simply that and he admits as much. Given my experience and observed oil pressure readings, even in heavy duty V8 applications (boats), I have not observed any indication of restriction (high oil pressure). Actually, I have observed the opposite at idle, kind of like what happens with low micron dust collection system filter bags. With much more area for the oil/air to flow, the net restriction is actually less.

 

Not having dealt with Toyota service lately, do they offer Mobil 1?

 

<div class='quotetop'>QUOTE(jtowndog\";p=\"78273)</div>

My local Toyota dealer carries Mobil 1 and Amsoil too, and is also an authorized Amsoil dealer. I guess they want to cover all the bases. Smart marketing.

 

<div class='quotetop'>QUOTE(popsrcr\";p=\"75816)</div>

The oil might be able to go further, but you still have all of that dirt in the oil filter. I'm a firm believer in synthetics, use them for all my cars, but I still replace the oil around 5000 miles with Mobil 1.

Dave
'84 Mustang GT
'02 Prius

 

The Prius in Europe has access to the same oil filters we do, and they have a 16,000km (10,000mi) factory recommended oil change interval with their recommended semi-synthetic oil.

How about the VW's over there that run up to 2 years or 50,000km oil change intervals? They're not changing the oil filter every 8,000km.

 

I used a sythetic blend after my first oil change. Just recently 25k miles i switched to full synthetic. I "flushed" the system with half a quart. Normally i save these half quarts, but i wanted to sacrifice it to get more of the older oil out. worked. In the end of the drain it did come out a lot more clear. I'm sure it only really flushed out 25% or so. if that even.

Now i get to test how sythetic hold out

btw.. anyone know why you get really good gas mileage at the end of the oil change? i recognized it's much easier to get the higher numbers toward the end of the oils life. less resistance?

 

<div class='quotetop'>QUOTE(jayman\";p=\"78349)</div>

I'm sure those VW's are diesels, correct? They do have longer service intervals than gasoline engines. I guess I mostly like the piece of mind it gives me to know that a few extra dollars will "probably" extend the life of my vehicles.

 

<div class='quotetop'>QUOTE(V8Cobrakid\";p=\"78363)</div>

Regular motor oils are made from a light base stock with polymer additives to increase the viscosity at operating temps. Eg: a 5W-30 is made from 5W stock and the polymers are used to approximate an SAE 30 oil at 100 C. AKA "Viscosity Improvers"

The polymers can suffer from an effect known as "shear" where the polymers literally are broken apart by normal mechanical sliding and rubbing friction within the motor. In severe cases, the oil can shear back to the base stock 5W.

So you may have put in a 5W-30, but it may have sheared to a 5W-20 or lighter by the time you were ready for an oil change. Eventually, the sheared polymers and acids in the motor react with each other and start to sludge up, then the oil thickens again. The API motor oil test assigns a "pass" grade if the oil "only" thickens 250% in their test.

Full synthetic oils have uniform composition and don't have much VI's in them. In particular, the Mobil 1 viscosity grades are somewhat on the "lighter" side of their rated viscosity, but they also hold up very well.

That's why folks claim increased fuel economy with Mobil 1: it's thinner to begin with, but stays in grade so you don't lose protection.

That's why I wouldn't be afraid to run something like the recently discontinued Mobil 1 0W-20: true it's right on the edge of what is considered a "safe" operating viscosity, but it has also been tested and proven to remain in grade for long periods.

Hope this helps answer your question.