Is it your MPG improvement TODO list?

Easiest way to block/disable EGR function on Volvo D12D engine is to block two 90 deg. bent EGR exhaus return pipes. I believe they are made out of brass and are very fragile, cost about $150-200 ea.

What you have to do is the following:
1. Remove underhood intake air filter assembly from you way, then unscrew heat protection harness as well.
2. Take off all four clamps that are sitting on the two EGR exhaust return pipes taking them off. These pipes are sitting on exhaus manifold.
3. Block at least one side of each pipe where it connects to exhaus manifold. The blockage either can be either welded into the pipes, or make round metal blockers that would fit between the exhaust manifold and the pipe end. I took a stainless steel stud that has its head a bit wider (4-5mm) than the inside diameter of the EGR exhaust return pipes, rounded the other side of the stud head and cut it off the bolt itself.
4. In order to reinstall the pipes back into their factory position you need to buy 4 metal gaskets at VOLVO dealership ($50 for 4). Thease gaskets are placed between the pipe ends and the exhaust manifold.
5. When putting the pipes back, install new gaskets and put your machined round blocker right between the exhaust manifold and the pipe end (just on one side of the pile that is attaching to exhast flow of the exhaus manifold), just inside the hole of a metal gasket. Put clamps on, tighten them, put hear protect harness, and air filter assembly.

P.S. Doing that you are permanently blocking backflow of exhaust crap back into EGRs -> air intake system. In most cases, if your EGR is in operational condition, it will continue opening and closing, heat sensor on the EGRs will tell your ECM all is fine.

DO NOT TOUCH neither EGRs nor EGR COOLER along with EGR HARNESS. YOU MAY DAMAGE WIRING, ETC.

This method worked for me and other guys, but you are doing that on your own risk. California DOT will ###### you when they take you in. But they will ###### you not for contaminating the air, but for letting your exhaust return outside better air, not just CO2.

GOOD LUCK! Two hours of work and max $100 in parts.

 

EXPLAINING # 3. "Slide trailer axles to the very front but keep compliant with DOT rules and regulations."

All US states and CAN provinces regulate max rear trailer axle position towards the very end of a trailers. Mostly, it is 9' between the edge of the trailer and middle of rear trailer axle.

Look at the document I attached.
Quote: "Semitrailers longer than 50 feet shall have a wheelbase of 37 feet to 41 feet (measured from the kingpin coupling to the center of the axles or to the center of the tandem axle assembly if equipped with 2 axles)."

In my company OTR handbook I have all that stated very clear.

 

Less air getting underneath the trailer to cut into the rear axle. Close the rear axle to the front, less air resistance to it. It adds very little to MPG, but if you want to get the max out of all the things together, you have to optimize your aerodynamics all the time where movable parts are involved.

Best aerodynamic invention for trailers - skirts.

 

Guys, just stumbled at one very good post at - http://ecomodder.com/forum/EM-hypermiling-driving-tips-ecodriving.php "108 hypermiling / ecodriving tips ..."

I bet many guys will like to read it and apply fuel saving techniques listed there.