So went back out tonight. It is coldish here in Phoenix, but the DA was the best I have seen yet. I set my tires to Mercedes recommended psi. 41 psi front and 33 psi rear while they were cold. That is what the other Merc guys say they are running.
I roughly had 4 gallons of 91 octane in the tank. I added two gallons of Sunoco 100 octane. Octane calculator calls it 94 octane.
I went on a 10 mile drive like I do every time to get the trans and oil temps up. Went to the spot.
It spun about 100 feet out. The 4Matic + gathered it up quickly but almost 2 tenths slower 0 to 60.
60 foot was 1 tenth slower, 1/8 mile was .15 slower but best mph, and the elapsed time was slower by one tenth. PR for mph. If it went what it does normally, that
pass is a low 10.80 pass.
I believe it would have been a low 10.80 pass because it picked up .32 tenths 60 to 130. I almost made it back up on the big end. It just goes to show how important short times are.
Couple of other observations. Usually when I run my passes it has been in the low 60's for temp and my tire temps are in the low 100's. Tonight it was 50 degrees and my tires temps were in the low 80's. Most of my passes have been with roughly a 1/2 tank. Tonight it was roughly a 1/4 tank.
My thoughts. I have good inclinations that it is making more power. Better fuel, colder temps, and good DA. Usually it spins 200 feet out. I think it spun 100 feet out tonight. To pick up .36 tenths from the 60 to 130 is a big deal. The tuner said it would run harder with 93/94 octane...boy was he right. I also think having less fuel in the car hurt the short time as well.
