Sorry for starting of with an oil thread

[LP_4Runner]

The owner's manual is always a good place to start with a vehicle. However, it DOESN'T always have the latest information. Typically, an owner's manual is sent off for printing months before a model-year vehicle is released. Things can definitely change. In addition (and this is almost always a cost-saving thing) unless a great many things change in the manual (or a recommendation in the manual will cause damage), they are rarely sent to be re-printed.

This is why I was somewhat contradicting the manual in another thread. Simply reading the manual is fine. But just quoting an owner's manual as the end-all-be-all of information is not always correct.

Its very possible Toyota had its list of changes for the 2007 manual already put together to be sent off when this change was made. They decided it didn't warrant the cost of updating the manual. Sometimes, you WILL see the manual that comes with the vehicle will have a supplement (or it MAY have even been changed mid-cycle...but not usually).

The worst part about all this is that service departments will often get confused as well. I'll give you an example (not Toyota related, but it happens to them as well):

In 2003 DaimlerChrysler made an early running change to the then-current production 2004 models for power steering fluid specifications. Previously they were using standard power steering fluid. They decided to change to ATF+4 in almost all power steering systems. However, there were a few exceptions. On the TSB (and training center documentation) the WJ (Jeep Grand Cherokee) and a few other models were to keep the previous power steeing fluid due to the types of seals used in their hydraulic fan systems. Technicians and dealerships didn't recognize this and started filling every vehicle with ATF+4 (with some resulting chaos). In fact, it still goes on today.

So the unfortunate part of all this is that owner's manuals are good sources of basic information. TSBs, one better. Reading very carefully all information you can get and piecing it together is the best thing you can do.

As a side note: The latest S/ grade certification of the oil changes on a regular basis. Any manufacturer will produce documentation giving the current S/ grade, but also specify that grade OR BETTER. So, if something says to use SL specified motor oil, then using SL or any specification higher than that (SM, etc) is a good choice.

 

[LP_4Runner]

Toyota, and some other manufacturers have adhered to the "don't switch back and forth" rule with synthetics vs. conventional oil for a single reason. When synthetic oil first came out some engines were found to have been prone to "leaking" a bit more with them. They found that an engine run predominantly with one OR the other type usually didn't exibit this issue. Only when they were switched back and forth (or changed late in the game). It was usually the switch from conventional to synthetic which showed the problem. There are a lot of reasons for this and a lot of it has to do with the effects of each type of oil on engine sealing materials.

Modern synthetics don't typically have this issue, but it can still occasionally crop up. To avoid potential oil-leak complaints most manufacturers would simply rather have you start early, and stick with one type of oil (conventional or synthetic).

Another reason is that some research has shown a slight tendency for synthetic oil to have a greater dissolving effect on conventional oil sludge or build-up. More specifically, the additive package "goodies" within them. The primary concern there would be along the lines of why you shouldn't put motor flush in a sludged engine. The sludge and build-up will break loose and clog up the filter. The filter goes into bypass and the contaminants then go straight for the bearings. Personally, I've never quite bought into synthetic having enough of an effect like this to be an issue. But, its somewhat out there.

 

[Chicago-Spike]

Synthetics don't cause oil leaks, they will however exploit a poor seal as the flow charecteristics are far superior to conventional oils. The synthetic will pass by the poor seal and make it seem as if the oil caused the leak. It is compounded even more when the mechanic switches back to conventional oil and the leak stops. It is then assumed that synthetic oils cause leaks, and they just do not do so.
The S ratings frequently change, and one does not have to find an oil that is the same letters like SK. If you have an oil that is rated SL it will work just fine for the SK engine.

 

[geenowalker]

neither will cause an oil leak, but if you use conventional and have a leak, and then switch to synthetic, it will be more pronounced. My friend had 72 Mobile 1 synth oil changes on his civic, and he just switched back to conventional because he got a leak (273K). The leak is still there, but much less of a pool on the ground.

 

[007Runner]

What I was trying to say is the 2007 4Runners on the dealers lots have written on the oil fill cap 5W-30. It does not not reflect the TSB, and the 2007 owner's manual calls for 5W-30 as well.
No insert for the owner's to reflect the TSB as well.

 

[GMZ]

Motor oil has to be changed between 3000 to 5000 miles , no matter which type you use (Synthetic or conventional)This is because the motor oil sees contamination from blow-by gases. Nothing in the oil can slow down this contamination rate from the combustion process.

I dont normally post up but I cant help myself. The 2UZ engine is one of the lowest wearing engines EVER MADE. A good dino oil will make 5K in this engine no problem. With a good syn you can run 10K easy, some even push it to 15K. M1 5W-30 in the 4.7L is a winning combo! Warranty issues aside of course : I used to run Syntec for 7.5K in my S/C 350Z and the lab I sent it to for UOA thought I was nuts for only keeping it in that long. Check out BITOG for even more info on oils.
Short version: the 3000-5000 mi oil change is a myth/wives' tale/quicky lube propaganda