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JasonG · 10-20-2010, 12:20 AM

Well i still need another tank and maybe some (grooaann) ABA testing,but anyway.
I'm a pre OBD diesel so i have to burn 25 gal to get numbers, no scangague here.

I added a full size tool box (pics tomorrow) to my truck when i changed to a 5th wheel and lost the fiberglass cap.
this is the first time in a while i have had a tank with no trailer.
it seems my avg trailerless MPG went fron 17 TO 19 MPG !

Normally:
the air from the top of the cab normally gets caught by the tailgate and rolled towards the cab creating the 'bubble' that guides the air over the tailgate forming a sort of tail.

My theory:
The tool box is rolling the 'bubble' up farther back from the cab. This is both causing the the slope to drop farther back as well as creating a primary shallower angle from the cab to the start of the 'bubble'.

Any thoughts or a nice simulation?

10-20-2010, 12:20 AM	#1 (permalink)
JasonG Master EcoModder Join Date: May 2009 Location: Charlotte NC / York SC Posts: 728 05 DMax - '05 Chevrolet 2500HD 90 day: 18.48 mpg (US) Thanks: 120 Thanked 56 Times in 52 Posts	Strange pickup aeromod ??? Well i still need another tank and maybe some (grooaann) ABA testing,but anyway. I'm a pre OBD diesel so i have to burn 25 gal to get numbers, no scangague here. I added a full size tool box (pics tomorrow) to my truck when i changed to a 5th wheel and lost the fiberglass cap. this is the first time in a while i have had a tank with no trailer. it seems my avg trailerless MPG went fron 17 TO 19 MPG ! Normally: the air from the top of the cab normally gets caught by the tailgate and rolled towards the cab creating the 'bubble' that guides the air over the tailgate forming a sort of tail. My theory: The tool box is rolling the 'bubble' up farther back from the cab. This is both causing the the slope to drop farther back as well as creating a primary shallower angle from the cab to the start of the 'bubble'. Any thoughts or a nice simulation? __________________ I can't understand why my MPG's are so low..........