fuel economy mods,tips & examples: congrats to David85 for hitting 25MPG!
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06-17-2010, 04:26 PM
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fuel economy mods,tips & examples: congrats to David85 for hitting 25MPG!
fuel economy mods,tips & examples: congrats to David85 for hitting 25MPG!
just thought id post these tips again and share David85's recent success for his 25MPG @ 55MPH (24.83 rounded up) road test posted over on OBN:
nice going David!
David's rig:
1986 F250HD Ex cab Fresh built up 6.9L diesel, Lariat AC leather seats power everything w/full cluster, sterling rear 3.08LS gears, E4OD trans, ram intake ATS 088 turbo
He swapped to 3.08 gears,and runs an E40D (fords auto trans w/ OD and a locking torque converter-the only auto overdrive trans offered as a direct bolt up to the IDI.however his year only offered a 3 speed auto stock.) with an aftermarket programmable pcm to control the shift points and tc lockup rpms/speed.
David also runs the famous "moose" injection pump,that is said to be meticulously rebuilt to the most stringent tolerances.
David has also stated in the past,that he has seen gains of an average of another whole mpg more when he removes his factory stock engine fan in the winter months.this test above was with the fan installed.
p.s.
iv been waiting a long time to get David,to slow down to 55 while empty.
Larger/free flowing exhaust
soup bowl mod
intake mod (via ram air or cowl induction)
ip and injectors changed every 100k.
oil and filter changed regularly (consider synthetics if you have the $ at the time.the less resistance,the better the mpg.)
skinniest tires you can live with and at max tire pressure (checked regularly)
have the engines timing checked by a reputable diesel shop at least every 2 years.(incorrect timing,can be a total killer!!)
keep the air cleaner clean (K&N air filter)
keep the wheel cylinders packed with grease.
swap out 4.10's for 3.55's if you don't tow monster loads regularly (by regularly i mean,at least hauling 5 ton at least once a week.)
swap out old 4 speeds for the E40D auto or the 5 speed stick ZF5 trans.
start out like grandma from your stops.watch stop lights signs ahead of you,as soon as you know the truck will coast to a stop to get there,let off the fuel!
keep it at or under 55 MPH (regardless of gearing,any faster the less efficient and more wind drag you have.)
keep the front end tight! ball joints/tie rods etc and regularly aligned.not doing so,can cost you big in MPG and tire ware.
if you do travel over 55 mph,you will NOT get the mileage you could have if you slowed down.if you do need to travel faster,lose everything that catches the wind,such as bug deflectors,sun visors,wide mirrors etc.
if you dont need it,dont carry it! the more weight you carry,the lower the mpg.it all adds up.
did i mention driving easy? lol.this the the biggest part.learn to hyper mile.learn to keep an even speed.when you get the hang of it,you can make the factory cruise control look horrible for fuel economy.
keep in the highest gear possible at all times,without the engine lugging (not a major concern with the grunt of a diesel.and w the auto,she will downshift on her own when it needs to.)
keep the rpms down,down,down.
consider a turbo,the more air in,the better the mpg (when not actually using the extra power.)
don't turn your pump up to roll coal! black out the pipe = wasted unburnt fuel.nothing more!
keep the E40D trans flushed and changed every 30k miles.transfer case and rear end at least every 100k(least the rear is every 100k not sure about the transfer actually.)
use fuel additive with cetane boost.the cost of the amount used,= over the cost of the lubricity to save pump and injector ware along with better mpg from the increased cetane boost.using the additive saves $.it doesn't cost $.
if you dont need a dually (regularly carrying more weight than SRW tires are rated for,at least weekly) then take off the duals and run single! the more tire drag,the worse the mpg.you can always put the extra two wheels back on when you get ready to hook up to that 5th wheel.
avoid excessive idling.(more than 5 mins just idling is all mpg going into the negative!)
running the A/C is cheaper when over 45 mph due to extra wind drag of having the windows down.
tint the windows(check you local law for max % first! a ticket isn't worth extra mpg gains!)
invest in some sound proofing/weather proofing.use it under everything.this means- a lower A/C setting can be used and still stay cool.
do the heater core bypass valve mod to stop coolant flowing through it during the summer months.
consider ditching that monster fan for a couple electrics mod.
based on the custom grind info,im going to say the "torque cam" will also increase mpg (it has too.it brings the power band down in the rpms a couple hundred,so you get max power without revving as high.)
have a pre 93 truck? consider upgrading to the 3G alternator.they are much more efficient.(dont expect to "see" the mpg gain.but it will be there.over years it all adds up.)
keep the electrical charging system corrosion free.wasted energy going into the alternator due to poor connections/corrosion will cost you $ long term.
running taller/shorter tires? then you NEED to recalibrate your speedometer.this throws your odometer off too,and your mileage calculations will NOT be correct!
soup bowl mod
intake mod (via ram air or cowl induction)
ip and injectors changed every 100k.
oil and filter changed regularly (consider synthetics if you have the $ at the time.the less resistance,the better the mpg.)
skinniest tires you can live with and at max tire pressure (checked regularly)
have the engines timing checked by a reputable diesel shop at least every 2 years.(incorrect timing,can be a total killer!!)
keep the air cleaner clean (K&N air filter)
keep the wheel cylinders packed with grease.
swap out 4.10's for 3.55's if you don't tow monster loads regularly (by regularly i mean,at least hauling 5 ton at least once a week.)
swap out old 4 speeds for the E40D auto or the 5 speed stick ZF5 trans.
start out like grandma from your stops.watch stop lights signs ahead of you,as soon as you know the truck will coast to a stop to get there,let off the fuel!
keep it at or under 55 MPH (regardless of gearing,any faster the less efficient and more wind drag you have.)
keep the front end tight! ball joints/tie rods etc and regularly aligned.not doing so,can cost you big in MPG and tire ware.
if you do travel over 55 mph,you will NOT get the mileage you could have if you slowed down.if you do need to travel faster,lose everything that catches the wind,such as bug deflectors,sun visors,wide mirrors etc.
if you dont need it,dont carry it! the more weight you carry,the lower the mpg.it all adds up.
did i mention driving easy? lol.this the the biggest part.learn to hyper mile.learn to keep an even speed.when you get the hang of it,you can make the factory cruise control look horrible for fuel economy.
keep in the highest gear possible at all times,without the engine lugging (not a major concern with the grunt of a diesel.and w the auto,she will downshift on her own when it needs to.)
keep the rpms down,down,down.
consider a turbo,the more air in,the better the mpg (when not actually using the extra power.)
don't turn your pump up to roll coal! black out the pipe = wasted unburnt fuel.nothing more!
keep the E40D trans flushed and changed every 30k miles.transfer case and rear end at least every 100k(least the rear is every 100k not sure about the transfer actually.)
use fuel additive with cetane boost.the cost of the amount used,= over the cost of the lubricity to save pump and injector ware along with better mpg from the increased cetane boost.using the additive saves $.it doesn't cost $.
if you dont need a dually (regularly carrying more weight than SRW tires are rated for,at least weekly) then take off the duals and run single! the more tire drag,the worse the mpg.you can always put the extra two wheels back on when you get ready to hook up to that 5th wheel.
avoid excessive idling.(more than 5 mins just idling is all mpg going into the negative!)
running the A/C is cheaper when over 45 mph due to extra wind drag of having the windows down.
tint the windows(check you local law for max % first! a ticket isn't worth extra mpg gains!)
invest in some sound proofing/weather proofing.use it under everything.this means- a lower A/C setting can be used and still stay cool.
do the heater core bypass valve mod to stop coolant flowing through it during the summer months.
consider ditching that monster fan for a couple electrics mod.
based on the custom grind info,im going to say the "torque cam" will also increase mpg (it has too.it brings the power band down in the rpms a couple hundred,so you get max power without revving as high.)
have a pre 93 truck? consider upgrading to the 3G alternator.they are much more efficient.(dont expect to "see" the mpg gain.but it will be there.over years it all adds up.)
keep the electrical charging system corrosion free.wasted energy going into the alternator due to poor connections/corrosion will cost you $ long term.
running taller/shorter tires? then you NEED to recalibrate your speedometer.this throws your odometer off too,and your mileage calculations will NOT be correct!
Well the moment we have finally been waiting for is here. I drove 55 MPH empty today.
I did something different this time to isolate the highway cruising and warm up period(s) completely from todays test. Basically I refueled before leaving town, then refueled immediately when getting back about 5 hours later.
So the first fuel up was 37.1L and 258km distance = 16.06 MPG - better than I expected.
That was a real mixed bag of urban driving, some mild highway driving and even some logging roads (lots of slow idling on roads I probably shouldn't have been on without a spare tire).
The second fuel up was for as consistent a run at all 55 MPH blacktop as I could get. Engine was at operating temperature when I headed out on this second fillup so today is probably about as good as its going to get.
30.95L for a distance of 332.7 km calculates to about 24.83 MPG.
As always, this is an average of 2 directions on the same length of road to get a good average that doesn't get inflated by a tailwind or some other factor.
This beats out my old record which was 22.5 MPG cruising somewhere between 65-70 MPH empty.
I did something different this time to isolate the highway cruising and warm up period(s) completely from todays test. Basically I refueled before leaving town, then refueled immediately when getting back about 5 hours later.
So the first fuel up was 37.1L and 258km distance = 16.06 MPG - better than I expected.
That was a real mixed bag of urban driving, some mild highway driving and even some logging roads (lots of slow idling on roads I probably shouldn't have been on without a spare tire).
The second fuel up was for as consistent a run at all 55 MPH blacktop as I could get. Engine was at operating temperature when I headed out on this second fillup so today is probably about as good as its going to get.
30.95L for a distance of 332.7 km calculates to about 24.83 MPG.
As always, this is an average of 2 directions on the same length of road to get a good average that doesn't get inflated by a tailwind or some other factor.
This beats out my old record which was 22.5 MPG cruising somewhere between 65-70 MPH empty.
nice going David!
David's rig:
1986 F250HD Ex cab Fresh built up 6.9L diesel, Lariat AC leather seats power everything w/full cluster, sterling rear 3.08LS gears, E4OD trans, ram intake ATS 088 turbo
He swapped to 3.08 gears,and runs an E40D (fords auto trans w/ OD and a locking torque converter-the only auto overdrive trans offered as a direct bolt up to the IDI.however his year only offered a 3 speed auto stock.) with an aftermarket programmable pcm to control the shift points and tc lockup rpms/speed.
David also runs the famous "moose" injection pump,that is said to be meticulously rebuilt to the most stringent tolerances.
David has also stated in the past,that he has seen gains of an average of another whole mpg more when he removes his factory stock engine fan in the winter months.this test above was with the fan installed.
p.s.
iv been waiting a long time to get David,to slow down to 55 while empty.
#2
06-17-2010, 06:31 PM
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#4
06-18-2010, 09:52 AM
A-huh, so you are the one who's been spreading rumors about me around here. 
All I keep thinking about is what I could have done to keep that 0.17 MPG and make it 25 even. Used the AC for a grand total of about 20 minutes that day. Wonder if that did it. Lots of red lights too.
I'm thinking to switch to a synthetic gear oil for the differential in the near future. Wonder if that would make any difference.
I am running stanadyne fuel supplement but I don't think this version is a cetain booster. Never tried a cetain booster.
Cruise control was used for probably 95% of the driving but I adjusted it a long time ago to have very limited pull against the throttle. On steeper hills (above 4%) the truck may not be able to hold speed from cruise control alone. On such hills I use my discretion as to weather I need to give the pedal a gentle nudge or allow speed to bleed off if its a short enough hill that momentum can get the truck over without dropping too low. 5% seems to be just over the limit for overdrive at 55 MPH. It will still hold steady with some encouragment, but starts puffing a little smoke so I hit the overdrive cancel switch and let it lock into 3rd for longer hills that are 5% or more.
I really can't be 100% sure if the new moose pump is playing a significant role here since I never attempted this type of driving before. The 22.5 MPG result however, was with the old pump. What I noticed however was a lack of consistency with the old pump when it came to the high end of the MPG scale. Sometimes I would get over 20 without even trying while on other days I would struggle to reach the high teens. My non scientific observation is that the new pump has established some consistency in the results that wasn't there before. I've heard that the timing advance curve can get sticky or unstable as pumps age and the advance/retard plunger was replaced in my pump. At the very least, I can say that the moose pump doesn't hurt MPGs over the stock pump if you drive it sensibly. BTW, my timing is completely by hear, I have no idea where it is exactly
One word of caution is that this is a mere 1 tank average on 50% of the tank's capacity so don't take the result as gospel just yet. So far, I haven't noticed any outliners in the results but that doesn't mean they can't happen either. I might be able to make the same trip again in the near future and that might help verify the result if I can score close to 25 MPG again on this consecutive fillup.
All I keep thinking about is what I could have done to keep that 0.17 MPG and make it 25 even. Used the AC for a grand total of about 20 minutes that day. Wonder if that did it. Lots of red lights too.
I'm thinking to switch to a synthetic gear oil for the differential in the near future. Wonder if that would make any difference.
I am running stanadyne fuel supplement but I don't think this version is a cetain booster. Never tried a cetain booster.
Cruise control was used for probably 95% of the driving but I adjusted it a long time ago to have very limited pull against the throttle. On steeper hills (above 4%) the truck may not be able to hold speed from cruise control alone. On such hills I use my discretion as to weather I need to give the pedal a gentle nudge or allow speed to bleed off if its a short enough hill that momentum can get the truck over without dropping too low. 5% seems to be just over the limit for overdrive at 55 MPH. It will still hold steady with some encouragment, but starts puffing a little smoke so I hit the overdrive cancel switch and let it lock into 3rd for longer hills that are 5% or more.
I really can't be 100% sure if the new moose pump is playing a significant role here since I never attempted this type of driving before. The 22.5 MPG result however, was with the old pump. What I noticed however was a lack of consistency with the old pump when it came to the high end of the MPG scale. Sometimes I would get over 20 without even trying while on other days I would struggle to reach the high teens. My non scientific observation is that the new pump has established some consistency in the results that wasn't there before. I've heard that the timing advance curve can get sticky or unstable as pumps age and the advance/retard plunger was replaced in my pump. At the very least, I can say that the moose pump doesn't hurt MPGs over the stock pump if you drive it sensibly. BTW, my timing is completely by hear, I have no idea where it is exactly
One word of caution is that this is a mere 1 tank average on 50% of the tank's capacity so don't take the result as gospel just yet. So far, I haven't noticed any outliners in the results but that doesn't mean they can't happen either. I might be able to make the same trip again in the near future and that might help verify the result if I can score close to 25 MPG again on this consecutive fillup.
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