14 mpg city 17 hwy?
 

Hi all. I'm back and tired of this poor mileage. I keep reading of people getting 18+ city with a 2nd Gen Cummins.

So let's compare apples to apples meaning auto 4x4 2nd Gen stock size tires (265's) 3:55 gears.
Truck is in sig and I drive like an old man on Sunday.

I've read about replacing a IAT and MAP to improve mileage but I've checked and cleaned both and they were clean so why waste the money, can they be tested Ohm or resistance readings?

What are you getting? My best, everything hand calculated, was 19.8 empty hwy.

'02, 150K miles, 200HP FireBallPro injectors, Edge Juice run on 1x1, towing twins, cam, springs, .020" marine gasket got me 23.4MPG 3 days ago round trip to Vancouver, WA from the Tacoma area.

My dad's 02 is bone stock except for a BHAF and a Diamond Eye exhaust with muffler just turned 18MPG going up to Bellingham from the same area.

Both truck 3.54 gears, auto, 265 tires. I do run a roll top cover, don;t know if that helps or hurts mileage. It just keeps my fishin stuff dry.

So, we are about sea level, temps range from the 30's to the high 40's. All mileage hand calc'd.

Dave

98 single cab auto 4x4 with 265/70/17 on 3rd gen aluminums, 220k, 150 jammer sticks,quad xzt+ and a tq lockup switch= 17 mpg hw 75mph

I'm getting the same mileage...

I would agree it's a little on the low side

The gain from replacing IAT and MAP can be substantial (I gained 3mpg on a MAP once) , but since you drive truck so little the money spent won't cover the difference in a short time.

It's up to you decide which is more convenient.

is this what you get year round or just this time of year.

I have a 99, 4x4, quad cab, long bed, 3.55 gear and auto tranny. I get 19 or so city and 22 or so highway. I have noticed my mileage is down a little in colder weather.

hook a scanner and check the boost pressure? my map was bad it read around 75 psi boost.

-dkenny

Winter fuel goes through quicker.

14 in the city sounds about right for winter fuel, (I'm down around 10 to 12, but am towing heavy in town and its cold out, -23). My last highway trip was 20.8 empty on winter fuel, empty (except for a dirt bike), but I had the whole front end blocked off and was cruising @ 69 mph. You could try making a winter front and make sure your motor is getting up to operating temperature. If the motor is not warm, you will lose 3-5 miles per gallon. If its really cold out, it will take about 30 minutes or so for the truck to loosen up and start giving you better mileage.

IMO, not gonna do 18 mpg with a 4x4 and an automatic and winter fuel... at least not in your city traffic.
I live in a southern rural area, with no winter fuel, and average 16.7 mpg. Use to get 17.1 mpg on 265's.
I only do 1000+ mileage tests for better accuracy.
Best ever... long 1,200 mile hwy trip to west coast... was 18.9 mpg at 75 mph.

RJ

Winter MPG - 14/17 at best (and that is with a bottle of 911 each fillup)
Summer MPG - 16/19 at best..
2nd VP
FASS LP
265 AT tires
K&N filter (no problems)
No chip
Stock Injectors

It gets cold here in NW Colorado - altitude is about 7K around town - got the Winter blues right now.
DD

Girlfriends truck
2002 Ext cab short bed auto 295 tires
13mpg

stock

Good info everyone.

A lot of posts about winter fuel I've read about before, but honestly I've never seen an improvement on "summer" fuel. I constantly get ~14 city and 17-19 hwy.

Now I think someone pointed out I don't really get the truck up to temp but about once a week. Short commute to work and this is my DD. So this would explain my city mpg but hwy???

I'm not disappointed at the ~14 mpg city but would like to improve it "if" possible.

Sounds like I'm stuck with it, due to my short mileage trips/altitude/4x4 and auto combo.

Thanks again.

I get 14-15 in the winter 16-18 summer mixed city/hwy about 50/50. 98 2500 4X4 12 valve club cab long bed.

milage
 

12.5 to 13.5 in the city I drive fast![coffee][coffee][coffee]

Before replacing my LP i was getting low 15's in town, now I get that running on stage 1 on my Hypertech (hot rodding). Before LP went bad i never got lower than 16 in town (winter or summer) hot rodding around. I have gotten as good as 24 while averaging about 70mph, while running 50/50 bio. all is hand calculated and adjusted 7% for going from 245's to 285's. with the truck in my sig.

You're mileage is right where it should be, the 20mpg+ are BS. 13-15 city and 16-18 highway. I've actually got 20 mpg once empty driving 55-60 mph. Must have been the correct temp/wind/fuel etc..

Wow, I need to look at whats wrong with my truck at work. Its an 02 3500 4x4 auto, 3.55, running 235s. No mods. Went to kansas city and back,(did a little running around around town, little idling) Total mileage was around 550 miles, and we hand calculated 13 mpg.
Any Help?

Something sounds wrong.... unless you were towing your GN.... had strong headwinds..... or were driving 90 mph. [laugh]
I'd check basics first, like good air flow (clean filter), properly functioning turbo, no fuel leaks, etc.

RJ

I've only had mine for about a year. Hand calculate every tank.

Same truck as original post (02 quad 4x4 LB Auto 3.55 w/265/75/16) and about the same mpg.

Lowest: 14.0 mpg (winter, lots of 4wd and hauling firewood, before exhaust and M3)

Best: 19.3 mpg (at 65mph)

4,000 mile road trip averaged about 18.5 mpg

I've seen very little if any improvement in highway mpg since adding the Quadzilla M3 and 4 inch exhaust. I even turned the M3 off for a couple of tanks and saw no decrease in mileage. City/rural mpg has noticable improved.

Dude, you live in Colorado Springs. Not exactly level ground at sea level.... Your numbers sound right on for short commutes on winter fuel at high altitude over hills and dales....

Your mileage sounds fine. I get about the same with the truck in my sig, which is the least fuel efficient of the 3/4-tons due to weight, 4x4, and camper shell. Just to put things into perspective, my last truck, which was the most fuel efficient of the 3/4-tons was a '95 reg cab (160 hp), long bed, 2wd, 5 spd, stock. Driving in the same city like an old man (5-6 psi boost from red lights) I got 18-18.5 mpg city. That was during the summer and I didn't always check my fuel economy back then, but that's what I got a few times. So now I'm getting 13.8 city in the winter with my current truck that is much heavier, more wind resistant, has a front axle and t-case (added resistance), while driving it faster, and having done some mods. It makes sense.

x2 on altitude . my altitude is 7000 feet.... i would say the average elevation where i drive is around 5000, and i get almost 20 with propane, 17 w/out

Check your speedometer to make sure its right on. Even a 5% difference will cause you to calculate your mileage incorrectly.

My truck gets 16-18 general driving around town, or up the coast, getting on it. I usually get 20 on the highway if I go 70-75 mph. Had a best of 22 on one trip...

I do mostly mixed driving--I use the truck for my construction business and some personal use. I generally get 13-14 mixed.

My truck weighs closer to 8k pounds with the ladder rack, tools, and other stuff I keep in it day to day.

The map sensor was replaced recently, and I had been running an xzillaraider up until a couple weeks ago. The pos xzillariader won't work right anymore even after sending it back to be checked out:( The new map sensor was installed because the xzillaraider was supposedly not working right due to low map sensor voltage, but that wasn't the problem and it was not necessary to replace the sensor for $70. No noticeable change in mpg with new map.

In hindsight, I wish I had never heard the name quadzilla. Should have gone all mechanical for gauges and just bought injectors and a boost fooler for the little bit of extra power and maybe some mpgs.

We'll see what the mpg is without the chip now, probably even worse.