All you 20+ mpg people
 

How many miles do you actually get before the low fuel light comes on? I usually get to 470-480 miles and by the time I get around to filling up I'm usually at 500 miles or so(35gal tank). Yesterday I had 502 miles and 30 gallons= 16.7 miles per gallon. I have ran from completely full to empty for the past dozen or so tankfulls consecutively and my best mpg has been 17.1. I have been driving incredibly conservatively to normal. Soooooo, how do I change my calculations so I am getting 20 or more mpg like everyone else or am I the only honest one? I dont want to hear any "change your fuel filter", "check gauges" etc jive talk either. The truck runs fine and is maintained fine. I want to see some complete tankful, hand calculated runs. [coffee]

Don't forget to recalculate for your tires. If your truck originally came with 245/75/16's, multiply by 1.08 for your actual mileage. If it came with 265's, multiply by 1.04. So if your truck came with 245's stock, the tank that you put on 502 miles and put 30 gallons in, you actually got a little over 18mpg ;) If you are talking about your 2001, how do you know the maintenance record if you have only had it for 2 months? Have you checked the air filter, fuel filter, differentials, transmission, MAP sensor, IAT sensor or anything else? I'm not trying to be a wise guy, but those things can have a big impact on mileage.

what gears in your rears?

the 3:73 vs 4:10 difference is where most folks have a HUGE jump, if you compare apples to apples.

I didn't even think about the gears [dummy] There can be a huge difference between 3:55's and 4:10's. The 3:73's weren't offered until 03, I think. If you are getting 18mpg with 4:10 gears, be happy [guitar] Most people I know with the 4:10's are getting 14-16.

My truck has 3:55's and I carry about 1000 lbs of tools daily...I avg 19 with about an even 50/50 hwy and city driving. I'm usually pretty easy on the throttle too. Best ever running empty from san diego to vegas I got 23.

.....not to argue but that is one nasty stretch to acheive those kind of numbers.

Best I've done was from Casper Wyo to Salt Lake. Figured at 22mpg but the wind was blasting from the east and I would have to say 80% of that trek is downhill.

I don't know about your truck but my 1st gen has a 7 gallon reserve once the light comes on so it will only take 23 gallons max once it says that it's empty. Calculate your milage based on how many gallons you actually pump not by the capacity of your tank.

In the owners manual (for my truck) it says the Low Fuel Light comes on when there's 20% left in the tank, which on a 30 gallon tank is at 6 gallons. Personally, if it's just back and forth to work (60 mile round trip in country to city and back driving/traffic), I start to look for fuel at 600 miles on the resetable odometer. But if I'm in unknown territory I start looking at 500 miles.
I agree rear end gearing plays an important roll in mpg. If you're looking for a mileage per gallon performer 4.10's in the rear end won't do ya any favors mileage wise.

The capacity of the 2nd gen tanks is more than the 1st gens ;)

How fast are you guys going when you get your 20+ mpg? I get a hair under 18 mpg doing 120 km/h (75 mph) with some city driving mixed in. Just wondering if you're driving normal, or actually trying for good mileage (going 55 mph or what have you.)

fuel consumption
 

Whats up all? I have a 96 12v that has 400hp at the wheels and i can drive 600mi on 36 gal. thats 17mpg, it doesn't matter if i drive with my head or without it thats what i get! Its lifted 5 in and im ridin on 37.5's with a 5 speed

I have been running tests with the different programs on my Smarty for about a month now. I track every gallon of diesel and hand calculate my mileage on every tank.

I made 23 on my last trip home to visit my folks. It was a little over 250 miles and I ran 70-80 the whole way with the smarty on 7. For the trip back I set it for the fuel saver mode and ran 70. I only made 20 on that tank.

Two weeks ago I set it on 7 and ran it a week in Houston stop and go traffic and made 17.5 running it hard.

Last week I set it to 5 and made 17.

I just updated my smarty flash and will be running one week on each odd number setting to check the milage. It will be mix of town and highway and traffic jam.

My truck with only the RV275's and boost fooler made 20 highway and 16 town running it pretty hard.

-Dave

First off, your 4x4 with 285's is going to get much different mileage than a 2wd with smaller tires.

I never run mine down near empty, as the fuel cools the VP44, and I like plenty of fuel.

I've averaged 19-20 miles per gallon in my truck since new. That's all driving conditions, city and highway, pulling trailer up to 5k pounds periodically too. I drive it between 60 and 65 miler per hour most times. The trick is to not use the cruise control. I drive by my EGT and boost guge too. Keep the EGT under 600 and boost under 10 and mileage will reflect it.

The 285 tires I just put on are hurting my mileage some. Too soon to know, but seems about 1 mpg drop due to the bigger tires alone.

All my numbers are hand calculated, as my truck doesn't have an overhead computer.

You don't have to run it near empty.
 

The best way to calculate fuel mileage is to fill the tank, reset your trip odometer, run any distance you want (the further before filling again, the more accurate the calculation, and any change in tire size from factory will effect your odometer reading, thus making your calculations inaccurate), next fill it up again, take how many miles you drove (your trip odometer) divided by how many gallons it took to fill it back up to the top. (example: drove 475 miles, took 23 gallons to fill it back up, milage = 20.65 miles to a gallon), but you have to start with a full tank and fill back to a full tank. I average 19 to 20, just running around empty and about 11 - 12 pulling a 34 foot long by 12.5 foot high, 10K lb. 5th wheel travel trailer. 98, unmodified 24V, 5 speed manual, with 3.55 rear gear, 2WD duelly.

Things that will effect your milage, driving style, auto vs. manual tranny, rear gears, tire size, load, 2wd vs. 4wd, terrain, stop and go vs. hwy, etc....

Agreed.... Maybe Vegas to San Diego (downhill):)

RJ

Gambino-My brother and I have had this discussion a lot of times also, so I feel your pain. I think you need to notice how people are getting better mileage than you are, they are driving 2wd's most of the time. This will make a huge difference-1 less axle, no transfer case, better aerodynamics etc. i hope this helps you a little bit.

I agree with the 2 wheel drive point. I have a 4x4 on 35s, and I don't get above 16 mpg all highway 68 miles per hour. I had stock tires, and I got about 20 without trying to drive for mileage. Don't tell me about the odometer correction, because I already know.

I get crap mileage when I am in the desert, and I get a lot better mileage when it is raining. I can get 550 miles to a tank when it is wet, and about 450 in the desert. I know my grandpa put water injection on his old propane truck for mileage.

I don't know how everyone else does it. I have owned 4 of these trucks now and I have NEVER averaged more than 17, and that's only when I'm EXTEMEMLY easy on the go pedal and never go more than 65. I thought this truck was doing slightly better than my previous ones, but now that I have more time in it, I am finding that it does not. I almost always average somewhere between 15 and 16. I'd be extatic if I only got 3 more mpg, but it never happens consistantly.

I've driven over 200k miles in dodge diesel trucks and my overall average for that time is right around 15 mpg, lower if you count towing miles. :rolleyes:

Driving how I normally drive, I get 15mpg or so. I babied it this tank(I actually oly ran 1/4 tank through it), and got 21mpg with the tire correction. Mixed city, and highway driving. I did get on it a little a few times, but nothing too much. My truck seems to be pretty good on mileage if you drive it right. I got 22mpg coming back from Indiana last year running 75 and 80mph. I wonder if the bigger turbo housing helps any? I have heard people say it can help; I guess cause it keeps drive pressure down? I dont know, but this is all hand calculated, and right. Im happy. My dad also gets 21mpg or so. His is bone stock

Eric

What the heck are you guys talking about with san diego to vegas being a nasty stretch? There are only 2 notable hills...cajon pass and Baker. Thats it, the rest is pretty much flat. My wifes toyota corolla got its best ever recorded mileage on the same route- an impressive 40mpg running 75 plus the whole way. The climb OUT of vegas on the 15 is worse than either of the hills running north.

At 75 mph I get 17 - 18 mpg empty. Driving 2 lane roads at around 60 mph I get about 20 mpg. Towing around 7000 lbs will put my truck in the lower teens. I have checked mileage both with the overhead computer and by hand.

Most of my driving time is on 4 lane highways or in rural areas. Used to live around a city but not anymore.

I get 22 mpg with mine and its a non lock up TC this while driving 65 on cruise never touching it. In my openion mileage is a crapshoot. I had a 1997 chevy z71 350/auto that would get 20mpg at 70 mph. My buddy had the identical set up, gears and all and could only muster 17mpg with me driving identically on the same route. IT just seems some machines work better than others even though they are supposed to be identical. thats my .02

wayne

I once averaged 26.9 MPG(Imperial)...but this was half secondary highways at 50 MPH and reg highway at 62 mph.
Never going faster, not many hills, very little traffic and driving like I had an egg between my foot and go peddle....empty of course.
2004 555 305 2wd 48RE lb...all stock.
It is possible to pull some high MPG...but not very practicle or fun...if not downright dangerous on a busy freeway.

I average about 19 mpg(imperial) city highway spread over winter summer.
Better summer, worse winter.

With my Smarty on sw 1, I averaged 20.5 mpg. On sw 3 I averaged 22.5 mpg. both of these are for mostly highway mileage running 340 to 400 miles in one day.

I went to Dallas this week from New orleans and got 20 on the way there going 75.

I went 65 on the way home and got 22.6.

A truck is a complicated machine.

But it is not a complex machine.

Its a lot like a girlfriend- ya got to romance it...[whistle]

Good mpg #'s, if you don't already have them, can be gotten by a lot of little things that add up to a couple /three mpg.

So look at it like this: a little here and there, a bit of this and that. Don't believe all that silver bullit bam instant mpg heaven stuff. The trucks that get the best mpg are well cared for, I'll wager. Plus every truck is a little different and each one will respond to your attention in different ways. If something you do makes the mpg's drop, go the other way or try something different.

In the end you'll get where you want to be, if you are patient.

[roll] Big Jimmy [eyecrazy]

Well said. Not only that, but there are differences even within tanks of fuel from one run to the next. There are way too many variables involved to have one "sure fire" method. I can tell you that with mine I can get anywhere between 18-22 miles per gallon. All are hand-calculated and I have done so ever since I got this truck 7 years ago. I find that it doesn't really matter uphill or down, loaded or unloaded (not talking about pulling 15K), it really has to do with your maintenance and how much you like to show off your truck. I would love to get more out of mine, but after this long, I don't think it's going to happen so I just enjoy driving it.

Ditto: I think our trucks must be coming from a different factory than the 20 MPG trucks. [laugh]

Herb, there might be something to what you say.

There might be enough tolerance in axle locations and overall assembly quality to possibly explain a couple mpg?

I don't think the engines vary that much, but the trucks probably have a LOT of tolerance.

Mine is hecho en Mexico, and I have one of the last of the Lago plant trucks-- superbly made. (you know a Lago truck because they are the only ones with factory undercoating under the cab, AFAIK).

Justin

i have had 3 assemled in St Louis and one assembled in El Taco

My fuel gauge is broken. I fill up at 600 miles if I have been driving empty city or highway.

But if I go all highway at 65 mph I can do 750 miles!

I am very curious to see how this truck does pulling a 19,000 lbs car trailer.

You can double your miles per dollar, move to a border town and buy fuel in Mexico at $1.77 per gallon

Since getting into the 30,000+ miles range, I get tank after tank 20+ mpg crusing my daily 120+ mile round trip commute. Usually I fill up between 600 and 650 miles and don't see the low fuel indicator come on. Now with your 4X4 and probably 4.10 gears (i'm 3.73 geared 2-wheel) I wouldn't expect the same mileage. The overhead on my truck is used for compass heading and temp. All mileage calculations are by hand.
The mileage is definitely helped by running the Triple Dog on Tow all the time.
The Tow setting is a timing advance and extra injection pulse.
Cheers
Mike
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In my 01 on the last tank i dident even get to 400 miles on the odometer. i have replace my IAt sensor, AFE stage two, new fuel filter, i dont know what else to do. I am running 315 tires but that wouldent kill my milage that much any opinions would be great

I was getting 19mpg average when I bought her, but after switching to synthetic everything (diffs and all) I noticed a difference. I also added a K&N filter and slowed from driving 70-75mph to 65-70mph. I am now averaging 21-22mpg with a 75% highway-25%city driving. I think the key for me is to just accelerate within a comfortable margin (I don't floor it from every stop) Even though I slowed my cruising down, in reality I only added a few minutes to my commute, and it is worth it for the extra mileage. I figure just drive it for what she is, a big 'ole diesel truck and besides, the more time I spend in her the happier I am!

Gambino
I have a 110 mile a day commute, drove this for 32 years, and the truck in my sig ,305/555 six speed,will average 22+ mpgs tank after tank. That is an average as this truck has put down some 23.5 + tanks on long cross country trips. All pencil figures and the truck has 55000 miles. The short road for me is I-44 and run 75 mph, max speed limit, with cruise on. I can use the mother road,old hiway 66 at 60 mph but fuel milage changes very little. This truck tows a 11200 lb 5er and averages 12+ mpg on the interstates. My previous truck was a '01 Dodge/Cummins 235/460 2500 QC 3.54 auto stock and on the same commute would average 19.5 - 20 mpg.
As some posters point out a 3500 DRW or 2500/auto/4.10/big tires/front brush guard/lots of extra goodies/city driving or heavy foot will not get the mpgs that someone with my hiway commute, no city miles, and a lighter 2500 truck such as the one in my sig. City driving is the biggest mpg killer on these heavy trucks.
Folks out here where I live that drive PSDs and a couple of DMAXs with some of the older 6.9 and 7.3 Fords are gettin' 20+ mpgs on our long commutes.
As far as miles on a tank of fuel I run around 500-550 miles and usually takes around 24 gal to fill. It doesn't pay to let our tanks get to low as sometimes its 55 miles to the closest fuel pump thats open.

JIM

Also, If made at Lago Alberto Plant....last letter in VIN# is an "M" (just before final 6 numbers).
Had not heard about them being better made, in any way....How so?

Mine is also Lago Alberto...but without undercoating, as best I can tell. Lived with a vacumm pump leak for 6 months so it's hard to be sure. :)

RJ

20+ mpg
 

Well, to give you an idea that my mileage is correct my guage is just below 1/2 a tank between 1/2 and 3/8 and I've put 425 miles on this tank so far. I consistantly get 21-22 mpg's in the summer back and forth to work and around town. Having the 6 speed gives me a big advantage. I coast down hills, and when I can in traffic. My quad chip seems to help mileage some times. I've got as high as 24.4 last year on a summer all highway 675 one day trip. I have synthetics in engine, diffs, and transmission. I run howes and mmo mix every tank. My mpg numbers are honest. The quad chip screws up the overhead by about 3mpg. For instance my last tank it said 25.2 on the overhead but the actual was 628miles / 28.1gallons = 22.348mpg. Not sure why some trucks get better than others.

:o :o :o :o My Z71 got 13-15MPG........20 MPG in your truck:o [laugh]

I just got back from a trip from Powell Wy to Jackson Hole and back and averaged 23.2 MPG in the truck in my sig. I just had the VP44 replaced and put the Fass on right before that. I think that made a huge difference alone, just having equipment that is working properly on these trucks plays an important role. Like somebody else stated, I coast downhills for the most part, and I only use cruise control out on the flats. Keep in mind that the speed limit on this trip varied between 35-55 mph for the most part (Mostly through Yellowstone), but I was very happy with the results none the less. I've noticed that I get the best mileage when I can keep my rpm's below 1900. So I will be looking for an aftermarket overdrive sometime soon.

BTW, I only run premium (#1) diesel fuel.