Second Oil Filter

I have switch to synthetic oil and and extending my oil changes 5,000 miles at the time until the oil analysis says not to.. So,

I pulled the cap off where the second oil filter go and the threaded part where the filter screws on has a hole that is only about an 1/8th in diameter. So I out the cap back on. The cat book says with every one gallon of oil added to the system adds 2000 miles to a oil change. It would have been nice to have the second filter. I am trying to get to 30K miles on an oil change with a lube every 15k miles.

 

I didn't change anything to change over. The motor only has 300k miles on it. I am using a blend called mystik. I didn't add the second filter. I am using a wix filter.

I was using chevron delo 15w40. I would burn 2 gallons in 15k miles. I just changed over so the mpg and consumption is t.b.d. On the first 700 miles it looks like .4 increase on mpg. to 6.8 mpg with a moffit fork lift on the back. I thought of amsoil until I checked the price. If mistik can't get me to 30K on an oil change I might switch to something else.

 

Blend and $12ish a gallon, It comes in a two gallon jug.

 

They know everything I have done to it. As long as there is no NOS bottles strapped to it or anything crazy.