I was told by the Lexus service manager not to put Full Synthetic Oil. Can anyone comment?

Used Mobile 1 in all of mine for the last 15 years; used it my BMWs since 1974 when it came out; my Lexus dealer has that as an option with each service; superior in every way to the regular dino stuff IMHO...

Your service manager obviously hasnt a brain, has he not heard of the famous sludged engines that Lexus/toyota has experienced???? Send him back to the Wizard of OZ and give him a brain.....

Not sure to which service manager lenore is referring (mine or yours!), but recommend the following link for info from this very forum:

http://us.lexusownersclub.com/forums/index.php?showtopic=741

Synthetic oil is a superior lubricant for all applications...

Excellent article. I do put Mobil1 full synthetic in my VW. What weight do you suggest for GX470? living in Arizona? 5W-30 or 10W-30 or 5W-40 or 10W-40?

Owners Manual recommendation is 5w-30, which is the weight I've always used with previous Lexus (3 of 'em) and BMWs (4 of 'em), everywhere from New Mexico to Central Germany, so AZ should be in the ballpark...no engine problems, ever, and 75-100K per each before trade generally; I change oil 3-5K even with synthetic; pretty cheap insurance....

No problems with full synthetic in both of my Lexi. Just use the weight called for in your owners manual.
However, you do need a new service manager.

steviej.

I only know for sure sync oil have better advantage over others, and they have been shown remarkable improvement over their performance . Some of the usual advantages are 1.Measurably better low and high temperature viscosity performance
2.Better chemical & shear stability. 3.Decreased evaporative loss . 4.Resistance to oxidation, thermal breakdown and oil sludge problems
5.Extended drain intervals with the environmental benefit of less oil waste.
6.Improved fuel economy in certain engine configurations.
7.Better lubrication on cold starts.

I only know one thing for sure that cold countries and the hotter countries have different grade in the sync oil for their automobiles. I have witness personally when I travel around the world on my business trips. BMW and certain Merc class cars come as standard factory fill of syn oil and the replacement interval is over a longer period than normal oils.

My advise go for it, no need to ask you lexus service manager. You will witness the change in your car smoothness.

So would you guys recommend Mobile-1 5W-30 for the GX?

Thanks

I belive they changed it already to 5W-20 instead of the 5W-30

I had a long chat with sewell dallas and they insisted that 5w-30 is the best ever for the current models since 2003. Seeing the viscoscity and its properties are quite similar, I cannot say why because it could be the oil temp variance & kinetic viscosity temp as this could hit the seals around and they do have some abrasive properties. This is purely what i studied.
The decision is still left with you to take the right one. If your vehicle is covered by a warranty , follow recommended oil from your service manager and go for the recommended one.

for me during summer ill use 5-30 but in winter times ill use 5w-20 since i usually do cold starting...i think for the warranty it doesnt matter if its 20 or 30 as long both are accepted by lexus

Um...I believe the "5w" is the cold weight....

ok here is an excerpt view, this should clear all you doubts.
Quote:The API/SAE designation for multi-grade oils includes two grade numbers; for example, 10W-30 designates a common multi-grade oil. The first number associated with the W is not rated at any single temperature. The "10W" means that this oil can be pumped by your engine as cold as a single-grade 10 weight oil can be pumped. "5W" can be pumped at a lower temperature than "10W". The second number, 30, means that the viscosity of this multi-grade oil at 100�C (212�F) operating temperature corresponds to the viscosity of a single-grade 30 oil at same temperature. The governing SAE standard is called SAE J300. The motor oil grade and viscosity to be used in a given vehicle is specified by the manufacturer of the vehicle. Unquote
Hope I this answers ...cheers

There must be something wrong with your service manager, I recommend finding a new one. HAHAHA