Gambino-01

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.

oestreich84

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.

04ctd

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.

oestreich84

I didn't even think about the gears 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 Most people I know with the 4:10's are getting 14-16.

HotRod82

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.

J BODY

.....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.

spunbearing

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.

chuxtruk

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.

oestreich84

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

Tate

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.)

strokethis96

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

GTSDave

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

KAyers

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.

pbolte61

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....

RowJ

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

RJ