Wrong Type Oil in engine?

Somewhere on the Gen2 threads we have a letter from Toyota USA saying the 5W-20 is OK, but Toyota said to stick with the Gen2 recommended drain interval, which I believe is 5000 miles (I go over 5k drain but I stick with the 5W-30).

This is hearsay but I am under the impression Gen2 may build up more fuel in the oil, so holding to the 5k limit with a lower visc oil may have some merit.

 

Yes I do not believe Toyota on the Gen2 differentiates between synthetic/dino on drain interval.

Just saying what Toyota said in the letter (which is by memory so caution)

 

If I can throw in my 2c worth.

I don't believe using 5W20 fully synthetic oil for the next 4,000 mi will do your engine any harm. As Patrick says, just monitor the level and top up as necessary. But from what you have said this is not a major issue.

In just about every other jurisdiction, Toyota's recommended oil change interval, using fully synthetic is 10,000 mi/15,000 km, so there is no harm from Toyota's point of view.

There are two reasons, in my opinion, Toyota USA "recommends" a 5000 or 8000 mi interval:

1. USA is a litigious business environment and using the lower interval considerably mitigates the risk;
2. Using the lower OCI provides for a 50% increase in cashflows from unnecessary oil changes.

That is, in my opinion, the simple truth.

By all means change your oil back to 5W30 ASAP or in 1000 mi, if that gives you peace of mind. It is your car and you will have to live with the consequences of your decision.

My belief, for the reasons stated above, is you can just wait until your next OCI. After that you could move to 10,000 mi OCI like the rest of the world and change your filter and oil each time.

BTW, changing only your oil filter mid interval is just over-kill. But if it floats your boat ...

 

Oil filter can operate a lot longer than the oil change interval. So there’s no point in changing the filter in between.

 

In the old days, when the Toyotas first appeared on the West Coast -- and actually had no ICE -- they were pulled by some of the Mt. Fujiyama snow monkeys -- IIRC --

It was change the oil every 2500 to 3000 miles and change the oil filter every other oil change.

I think that continued on up into the early 1980s, at least -- anyone recall this?

 

Honda at least, continues to preach oil filter change at every second oil change. The cars have an in-dash maintenance alert that comes up periodically, alternately service "A" or "B":

 

I used 5W-30 and then recently bought a Camry hybrid 09 and the Camry recommended use 0W-20. But guess what, it burned oil so fast. I have to constantly add oil on my Camry every 500-700 miles.Then I tried AMS oil and first 1000 miles the oil consumption increased and then slow down. Now my Camry does not burn as much oil as what it used to be consider the fact that I have never change the PCV value. I just change the PCV value and will see what happen. By the way, I think you can simply search of Camry burn oil on Google and you will most likely found a lot of people complain that Camry from 06-11 has oil burning issue. I am not sure if they all replace PCV value. but the key to modern Toyota engine is change oil and PVC value in my view.

I also tried to use 5W20 (AMS oil also) on my Prius and I found that it burned more oil initially and then slow down. so my theory is 0w-20 is thinner oil and it is able to go into narrow gap between the piston wall and piston ring or something like that to remove all the sludge and therefore help to clean the engine. But during the process of sludge removal, the gap between engine wall and piston ring increase and therefore oil burning increase. BTW, I was using AMS oil. and it is expensive.

So here is my recommendation. Use 0W-20 (or 5W-20) only if you watch your oil from week to week, check oil level at least every 300-500 miles.
Replace your PCV value.
Use good oil.

 

The one issue I've heard with burning excessive oil, is that it can clog the catalytic converter, so if thicker oil burns less, maybe the better choice once the engine starts consuming significantly.

 

There are plenty of people that use 0W20 and don't have any issues with their engines using oil. However, some people after using a 5W30/10W40 dino oil for many thousands of miles and then changing to a synthetic 0W20 have noticed an increase in oil consumption. So may be this is what you're observing.

I don't think really there is any real science to your hypothesis, if you have an engine that uses oil then there is something more to it than using a lighter oil. It is possible that there is a placebo effect in play in that you may have always burned oil but never noticed it before, but since changing to 0W20 you are paying more attention and are now noticing that it burns oil.

Check your oil levels frequently and use good (not necessarily expensive) oil—that is good advice.

 

if that chart is for the prius I would say its probably good to use it as a guideline. just the same 0w20 syn isn't gonna hurt your engine above 20f. unless you forget to check it. if that chart is for the prius, that means I could safely run 10w40 all year, but I wouldn't even consider 10w40 unless I had like 300k and it was using oil.

 

Not sure where that one came from, but here is the one from the Australian user manual for my 2005 Prius. Also included for comparison is the one for my 2005 Mazda 2 (In the US I think it was called a "Mazda Demio" btw).