An Observation

[RTexasF]

Now at 12500 miles I have run Red Line 10W30 since 1000 miles in an '03 Corolla 1.8L 5 speed manual. Two changes during the interval, one @ 6K the next @ 12K. Recently I changed to 10W30 Mobil 1 due to price and availability. Mind you, I thought nothing of it when changing from one synthetic to the other and had no presumed expectations other than saving a few $$.

What I noticed immediately after changing to M1 and starting the car was how much quieter the engine was. This "hushed noise" was also noticeable on those days when you have got to get with it to merge even though the engine is still cold. With the RL the engine protested with a rattle (valve train, pistons?) at about 3000 RPM. Now there is no noise at all. This is not my common practice to push a cold engine but we all occassionally have to stand on it to blend into traffic, cold or not.

Could this silence of the limbs be traced to the RL being on the Thicker side of 30 weight and M1 on the thinner side? The change is definite but I'm curious as to why.

 

[Drew99GT]

That's odd. Most people notice the opposite; that Mobil 1 makes their engine noisier. I'd call it good and sleep better at night

 

[unDummy]

I've compared syntec to mobil1 in one of my cars.
Mobil1 was quieter cold.
Syntec was quieter hot.
Since people know that engines are a little noisier when cold, guess which I'll use when its time to sell/tradein.

Was the same filter being used?

 

[RTexasF]

Yes, Toyota filters have been used from the start.

 

[RTexasF]

Well, obviously this topic did not strike any interest in the crowd. I thought it unusual since many reports (as noted in the few responses) observed more noise with M1. I guess we will never know.

 

[Chris B.]

My 2003 5.3 V8 Silverado seems to run good on Mobil 1 10w30. UOA will confirm this in the next few weeks!