In a nut shell

[TeachMeToMPG]

I have a 2010 BMW X5d that gets a decent 27mpg right now. I am searching for better. I am purchasing a 2000 VW Jetta TDI that is reported to get 45mpg.

My main goal for being here is to find the best way to boost those numbers as fast as possible. I drive 128 miles a day to work and home. 98% of that is highway at 60&70mph.

I would really like to learn about water/meth injection, propane, cooking grease and compressed natural gas as fuel source or supplemental fuel sources. With current and projected fuel prices, I need to make this commute worth while.

I have 13 years of military service. 2 tours to Afghanistan. I teach Aviation Maintenance now.

Thank you,
Russell

[RustyLugNut]

I suggest you start with the search functions. There is over a decade of information in these threads. Any other questions are often answered with some patience.

Again, welcome

[freebeard]

My main goal for being here is to find the best way to boost those numbers as fast as possible.

Thanks for asking. In Ecomodding terms there are three variables, aerodynamics, powewrtrain and the 'nut behind the wheel'. In Aviation terms you have airframe and powereplant.

Given your use case, aerodynamics is paramount (vs weight and rolling friction). There isn't a lot of 'low-hanging fruit'. The biggest single mod would be a full boat tail. Which brings with it a whole bag of woes, overall length and weight, etc.

Lesser strategies might include a front splitter and rear fenced difusser (for balance) or a drag-reducing teardrop vortex-degenerating pusher trailer.

Which of the two vehicles are you focusing on? FWIW, I just sold a 45 MPG VW diesel:

[TeachMeToMPG]

Originally Posted by freebeard

Which of the two vehicles are you focusing on?

I am looking at doing my best on the MK4 TDI Jetta.

Out the gate I am planning on bringing the tires from 205s to the stock 195s as thr seller suggested. I have a maintenance kit on the way from FCP Euro(amazing site. 100% lifetime warranty on everything), and the hammer mod to reset the adaptations in the injection pump. Hopefully full deletes this spring with 2.5inch turbo back exhaust this summer.

Im all ears on proven suggestions. I've thought about a full under tray to reduce wind drag, saucer style rims or hub caps, new wheel bearings to lower rolling friction as best as possible.

Have not searched a nose splitter yet but will now.

I had not considered the boat tail yet. Ill have to look more into that.

My goal is to build ecnomy on a budget. I will do all my labor and hope I get it right.

[freebeard]

For the notchback sedan, a hitch-mount tail box:
ecomodder.com/forum/showthread.php/project-ecofamily-civic-its-aero-hitch-box-boat

[cRiPpLe_rOoStEr]

Originally Posted by TeachMeToMPG

I would really like to learn about water/meth injection, propane, cooking grease and compressed natural gas as fuel source or supplemental fuel sources.

Methanol is mostly used in order to prevent freezing, and it also leads to an easier vaporizing of the water. In order to prevent cavitation of the metallic components of the water/methanol injection, de-ionized water is recommended.

I'd take propane with a grain of salt, and if I would ever mess with it in a Diesel I'd try liquid-phase injection.

Cooking grease may be easier on the VW than on the BMW. Have you ever heard about Elsbett? It used to offer vegetable oil conversion kits for many Diesel-powered vehicles and special machinery, and among the few engines with direct injection to which Elsbett supplied single-tank fuel systems which didn't require cold-starting with regular Diesel fuel were some Volkswagen and IIRC Renault engines. But anyway, nowadays due to the risk of an increase of DPF clogging, even though I'm favorable to vegetable oils as a motor fuel, I'd take it with a grain of salt too.

Supplemental CNG injection became more usual in my country in recent years. Even though it used to be more usual in Rio de Janeiro and São Paulo, I have already seen it in Rio Grande do Sul and Santa Catarina.

I have 13 years of military service. 2 tours to Afghanistan. I teach Aviation Maintenance now.

I studied Aviation Maintenance, and some of my teachers had a military background. There were also other teachers who, even though I'm not sure if they had any military background, they worked at Varig.