My journey to 40mpg with a 1ton diesel.

[mikeyjd]

Originally Posted by Diesel_Dave

I'm not sure how many miles you put on the truck, but a 40 mpg tank is 1,400 miles--so just driving a 40 mpg tank can take a month.

BTW, I have to ask a couple questions. Where do you live (climate wise) and what type of driving do you do with the truck? These things will determine what types of mods may be off-limits for you and also what types of numbers will be acheivable. I personally do mostly commuting with my truck (kind of a waste, I know). I see you have a Festiva as well--I assume that's your commuter vehicle.

Thanks for taking an interest Dave. I live in grand rapids, mi so guess we'd have fairly similar climates. My truck is for work/hauling/commuting. I do use the festiva when I don't want or need the utility of the truck. I guess I wasn't planning in taking it one mod at a time necessarily, but I can see the where there's some benefit and wisdom to a slower more well thought out and planned process. My next mod that I hope to finish tomorrow is my push button kill switch. I have the switch and wiring ready to go, so its just a matter of getting out there and doing it now

[JQmile]

40mpg is a really tall order. I have a low 2wd with a crap ton of timing, and I've gotten a best of 27mpg at normal speeds. At 40mph I might be able to get some crazy mpg numbers, but I don't have time for that. Start with 30mpg and go from there.

[mikeyjd]

Originally Posted by JQmile

40mpg is a really tall order. I have a low 2wd with a crap ton of timing, and I've gotten a best of 27mpg at normal speeds. At 40mph I might be able to get some crazy mpg numbers, but I don't have time for that. Start with 30mpg and go from there.

"Aim for the moon, even if you miss, you'll land among the stars".

Don't misunderstand the title. I don't feel that this project is 40mpg or bust. It is more of a long term goal. Obviously since I haven't recorded a 2nd fill up yet. I don't even have a hard baseline established yet. All I know is that I'm gonna do everything I can that isn't beyond reasonable to get my fe where I'd like it. At this point, other than a $4 kill switch, I haven't invested anything beyond the purchase price into it ($2,500), which leaves me about a $1,500 budget. I'll find out today, when I fill up, just what I'm really up against as a baseline. I plan to take the topper off for my next tank to compare with/without that as well.

[Diesel_Dave]

For what it's worth, it took me 14 months to go from 25 mpg to my first 40+ mpg tank.

[mikeyjd]

Originally Posted by Diesel_Dave

For what it's worth, it took me 14 months to go from 25 mpg to my first 40+ mpg tank.

Sounds like a best case scenario then since I have limited mechanical expertise, and I'm basically just trying copy you guys

[kafer65]

Interesting that the discussion regarding getting better mileage driving at 45mph with the diesels. I've always heard keeping rpms under 1800 was best. Also learned later on my TDI that even lower is not normally damaging and even better for mileage especially when your using your engine gently increase your coasting. I have to watch the rpms to ensure my overworked cam lobes are getting enough oil, so I feel more comfortable staying above 1100 rpm even though I still have enough torque to pull at idle. I've also noticed this also applies to gas engines as well. My D150 is going along nice and easy at 45mph at just under 1800 rpms. Once you get going above that the gearing and the poor aero really start to work against you.

[mikeyjd]

So I woke up early and got this kill switch done before heading out. It was really the easiest/most pressing mod for me since I hadn't been able to eoc yet, because i bought the truck without a working engine off solenoid. So far its working like a charm and I can't wait to put one in my Festiva as well :-)

[kafer65]

Color me jealous! Five speed, kill switch, you even still have the stock floor mat and a radio! I had a ridiculous time getting the wipers off of mine too. I still have the grill off from where I replaced the plastic wiper knuckles.

[Diesel_Dave]

Originally Posted by mikeyjd

So I woke up early and got this kill switch done before heading out. It was really the easiest/most pressing mod for me since I hadn't been able to eoc yet, because i bought the truck without a working engine off celenoid. So far its working like a charm and I can't wait to put one in my Festiva as well :-)

Am I right that 91 was pre-ECM? What exactly are you switching with the kills switch? Is there an electronic fuel cut off?

[mikeyjd]

Originally Posted by Diesel_Dave

Am I right that 91 was pre-ECM? What exactly are you switching with the kills switch? Is there an electronic fuel cut off?

Yes I do believe that the kill switch is cutting off power to the fuel sending unit, but I think maybe its actually cutting off all the electric from the battery since all my electronics are killed until I do a half click of the kill switch to bring them back along with the fuel feed. I'm not sure if this is ideal, but it sure beats having no eoc capability and just plugging the electric in with a janky old connector that the previous owner had set up when the engine off Solenoid went out.