What is the factory fill oil?

I changed my oil about 1000 miles ago, and used Mobil regular (Drive Clean 5000) oil, 10w30* as the manual says.

I've noticed a drop of about 1-2 mpg since then, and my driving conditions have not changed significantly. Looking at the graph of my mileage data it is pretty clear--it dropped immediately after the oil change, by about 1.2 mpg.

Is the factory fill a 10w30 conventional oil? Or is it something else (partial synthetic, lighter weight, etc.)?

*Edited to add: I had my viscosities mixed up. Manual calls for, and I put in, 5w30.

 

wow thats really strange. never heard of this happening before. I run Mob1 5-30 in my truck since the 1st change and its always been good in mine. Are you sure there wasnt some other change? Like maybe they changed to winter fuels in your area, or you got gas with 10% ethanol or something like that.

 

I may be wrong on this but I think I remember someone saying they use Mobil one 10w30 out of the factory.

As far as the MPG's, you also have to take into account of different fuel mixes for different times of the year, but you could be right that it could be the oil. But basically what I'm trying to say is that there are many different aspects that could effect that.

I would suggest for your next oil change is to go with Mobil 1, most people on here use that oil.

 

Tire inflation is fine. My standard practice on new vehicles is to use conventional oils until 5000 miles have passed, and then switch to synthetic on the next oil change. I usually use Mobil 1, but I couldn't pass up a deal on the Pennzoil Platinum synthetic when Wal-Mart was selling it for $20 with a $15 rebate...so the first two synthetic changes on this one will be with Pennzoil.

My owner's manual and oil fill cap both say 10w30 across all temp ranges. I was surprised it wasn't 5w30 or 5w20.

ETA: I'll find out soon enough. I changed the oil at 3700 miles, and I am going to split the difference between then and 10,000 miles to get me back on the normal maintenance schedule. So, I will be changing it at 6800 miles, and again at 10,000. I'll use Pennzoil Platinum both times.

 

Weird, mine is an '09 V6 and calls for 5-30. I did the oil change about 800 miles ago and notice no change in MPG.

 

Never mind, I had it backwards--I originally thought it would take 10w30, but the manual specifically calls for 5w30 across the whole temp range. I put in 5w30 Mobil Drive Clean 5000 oil.

Anyway, it sounds like maybe Toyota uses a better oil for the initial fill. I have a bottle to send for an analysis--maybe they can tell me!

 

If you find out which oil TOYOTA use out of factory, would you post it here.

 

Yeah, I have my sample bottle sitting here waiting for me to send it in. I'll post whatever results I get.

 

My truck calls for 0w20 or 5w20. Dealer told me to use 5w30, but I go by the fill cap. Always have.