MMRanch wrote on 11/03/21 at 20:31:22:So , if I have a hard time getting T6 oil then can't I just add some flat tapper magic to another oil .
I am thinking of going to 10w30 next time to see if the MPG numbers go up . If there is no improvement then I can always just add a can of STP to thicken things up a little again.
If you can't find any Rotella T6 on the shelves - then maybe you can do what I did and order it. The Tractor Supply had nothing on the shelves for months - but I was able to order it online and it was delivered to the store in a week. I have been able to find the T4 on some shelves and it works fine as well.
I am no longer a fan of adding ZDDP to oil. Too many of the ZDDP additives are not compatible with the wet clutch as they also contain Moly or other friction modifiers. Once you opened the bottle of Redline ZDDP a pink sludge would settle to the bottom of the bottle, and you could not shake it up as the layer became stuck to the bottom.
I also believe the Mobil1 4T motorcycle oil is a great oil......it costs about $10 a quart....so it is about 3 times more expensive than Rotella T6.
https://www.mobil.com/en/lubricants/for-personal-vehicles/our-products/produc...I don't think that adding STP to thicken up the oil is a good idea....using the proper weight oil will likely provide better protection. Additives take the place of the oil molecules....so adding things results in less actual motor oil molecules. (That is why break in oil has very little detergent additives and no "multi-viscosity additive"......it has more oil molecules to provide maximum lubrication).
As the oil chart shows, 10W-30 is an acceptable oil viscosity to use in the Savage provided the air temperature doesn't get over 86....so I would not use it as a summer oil. I really don't think you are going to realize much of an improvement in MPG by going to 10W-30. If your engine has some wear - you could see a bit more oil consumption by going to a lighter viscosity oil......but there is little reason to expect that 20W-50 is a better oil just because it is thicker. I used 15W-40 weight as it is suitable for all temperatures.