With respect to the original question, was there a conclusion in here somewhere?

I changed my oil and filter for the first time today and I went with 5-20 GTX at 1,939 miles (I always change my oil at 3000 mile intervals).

You can only get 0-20 in synthetic.

Make sure you have a big pair of channel lock pliers as the original Toyota filter has no prevision for a socket like the K&N filter that I replaced it with.

FWIW, my dealer told me that they do not use synthetic.

The compatibility problems with Mobil One and valve, and other seals, were quite serious in the beginning. Reformulation of the Oil and the valve seals eliminated this problem a few years later. Over the passage of time, this was forgotten (hardly anyone remembers the Firestone 500 debacle, or the Gould Nickel-Silver car battery now). I used Mobil One in that time period, and it worked well for me, although not for others. I do remember car dealers telling me that they would not honor the warranty if I used Mobil One.

i have been using mobil1 0w20 over hondas conventional oil for the last 5 oil changes.

i dont know how to put it , but it just seems better for some odd reason.

I will shed some light from an experienced person using Mobil 1 fully synthetic oil for the last 13+ years in my Toyotas including Camrys. It is one of the best ones with no issues so far. The switch to 100% fully synthetic Mobil 1 was always after the first oil change from Toyota manufacturer. The oil grade was 10W30, now I use 5W30 (06 Sienna) and will be 0W20 or 5W20 for my future 07 TCH.

Yesterday I took my Camry Hybrid in for its first oil change at 2019 miles, but 5 months old. I mentioned to the service tech that it required 0W20 or 5W20 grade oil, and he told me that they would use the proper oil. Unfortunately, I looked at the invoice completely after I got the car home and it said that they used bulk 10W30 oil. They do a lot of oil changes on Saturday mornings and say that they only have one person doing oil changes on Saturdays(the day that most people bring in the car for oil change) so, it must be like assembly line, yet takes several hours to get it done. I have e-mailed the service department to ask them to explain why they did not use the recommended oil. If Toyota allows the dealers to sell the hybrids, they should require them to follow their recommendations on servicing these vehicles. If my engine is damaged and the invoices show that they used 10W30 oil, what will this do to the warrenty, and to my extended warrenty. I also, prepaid for the 1st year of service, including oil change. This is suppose to be the best dealer in my area.

Hmmm, sounds like you need to complain to Toyota about that dealer. Not sure if it'll help - but it doesn't sound like the dealer is doing what Toyota expects.

Much has ben written here about this issue. I had a similar experience, and when I presented the service manager with the invoice showing the wrong oil, he immediately took the car back in the shop and changed to the correct viscosity oil, and gave me a certificate for a free oil change for the next time. BTW, the service advisor tried to tell me it was just a clerical mistake, they had actualy used the correct oil, just marked it on the invoice wrong! Riiiiiight.....

If it were me, I would speak to the service manager and request that they remove the incorrect oil, and put the proper oil in your car. Toyota specified oil type 0W20 or 5W20 for a reason. Make sure your TOYOTA dealer is following Toyot's recommendations.

Thanks for the input. The service manager replied to my e-mail and said that he checked it out and that the technician used the bottled 5W20 oil and not the bulk 10W30 oil and that the mistake was on the invoice from the parts department. He said that if he even thought that they had used the 10W30, that he would replace it immediately with the correct oil. I guess I will never know for sure.