Gas Mileage

smokinjoe · Post by **smokinjoe** » Mon Oct 13, 2003 3:56 pm

Does anyone else get the kinda mileage i do... i get about 220 230 to a tank city driving,i only drive about 20 miles a day so i dont fill up very often but i was just wondering if this is normal.ive got a tonneau cover on so i know it helps a little and im sure my tires kinda eat some so i figure i am back to about stock mileage. id figure for an s-10 id do a little better

adrenalnjunky · Post by **adrenalnjunky** » Mon Oct 13, 2003 4:36 pm

I only get 260-280 per tank city driving -- course I have a blazer and I'm not sure what size the tank is, but the 2004 Chevy Blazer spec sheet for the 4 door 4x4 lists it as approx 18 gallons.

I do find it funny that the Blazer is a 2004 vehicle, yet you don't see any on any of the local dearler's lots.

Especially with Chevy producing a 2-wheel drive ZR2 for this season -- why the effort to make a new model for a vehicle that should be phased out soon?

Crew02 · Post by **Crew02** » Mon Oct 13, 2003 8:34 pm

I drove home from Richmond VA this afternoon. I filled up in Richmond, and 305 miles later rolled into my driveway flat on "E" with the low fuel light stareing at me. Too tired to stop.

It was interstate all the way tho, not a good benchmark.

a2b · Post by **a2b** » Mon Oct 13, 2003 9:43 pm

sounds right, you got 3.73 gears?
try a lighter foot and not going over 55mph

melloyellow · Post by **melloyellow** » Mon Oct 13, 2003 10:01 pm

a2b wrote:sounds right, you got 3.73 gears?
try a lighter foot and not going over 55mph

Without the above is their any way to increase the milage on these trucks? I would like to force it up to 20mpg.

AZS10Crew · Post by **AZS10Crew** » Mon Oct 13, 2003 10:52 pm

melloyellow wrote:
a2b wrote:sounds right, you got 3.73 gears?
try a lighter foot and not going over 55mph
Without the above is their any way to increase the milage on these trucks? I would like to force it up to 20mpg.

Add 50 to your mileage before you pull out the calculator.

a2b · Post by **a2b** » Tue Oct 14, 2003 12:14 am

AZS10Crew wrote:
melloyellow wrote:
a2b wrote:sounds right, you got 3.73 gears?
try a lighter foot and not going over 55mph
Without the above is their any way to increase the milage on these trucks? I would like to force it up to 20mpg.
Add 50 to your mileage before you pull out the calculator.

50?
lord, he's only a bit off. i might add 15miles tops...how did you come up with 50?

a2b · Post by **a2b** » Tue Oct 14, 2003 12:17 am

melloyellow wrote:
a2b wrote:sounds right, you got 3.73 gears?
try a lighter foot and not going over 55mph
Without the above is their any way to increase the milage on these trucks? I would like to force it up to 20mpg.

intake and exhaust.
the best intake is the K&N FIPK2
get a good exhaust. flowmaster.....
then get a HPIII
then run light road tires...
run electric fans...(big HP gain)
dont run a/c
take off body lift

Crew02 · Post by **Crew02** » Tue Oct 14, 2003 5:21 am

Ok, I filled up this morning, and it took 15.4 gal. At that point milage was 310, so 310 / 15.4 = 20.12. But most of that was at 75- 80 miles an hour.

AZS10Crew · Post by **AZS10Crew** » Tue Oct 14, 2003 8:26 am

a2b wrote:
AZS10Crew wrote:
melloyellow wrote: Without the above is their any way to increase the milage on these trucks? I would like to force it up to 20mpg.
Add 50 to your mileage before you pull out the calculator.
50?
lord, he's only a bit off. i might add 15miles tops...how did you come up with 50?

Just a random number...

It would increase the mileage though.

a2b · Post by **a2b** » Tue Oct 14, 2003 8:41 am

AZS10Crew wrote:
a2b wrote:
AZS10Crew wrote: Add 50 to your mileage before you pull out the calculator.
50?
lord, he's only a bit off. i might add 15miles tops...how did you come up with 50?
Just a random number... It would increase the mileage though.

ooooohhhhhhhh

i thought you were bringin up the fact that he has 30's and that his odometer doesnt show all the miles he's actually putting on his truck

Crew02 · Post by **Crew02** » Tue Oct 14, 2003 9:45 am

Nope, odometer is correct. Reset with the Hypertec Programer.

AZS10Crew · Post by **AZS10Crew** » Tue Oct 14, 2003 12:21 pm

a2b wrote:
AZS10Crew wrote:
a2b wrote: 50?
lord, he's only a bit off. i might add 15miles tops...how did you come up with 50?
Just a random number... It would increase the mileage though.

ooooohhhhhhhh
i thought you were bringin up the fact that he has 30's and that his odometer doesnt show all the miles he's actually putting on his truck

Nope...just a quick and easy way to increase your mpg.

smokinjoe · Post by **smokinjoe** » Tue Oct 14, 2003 12:43 pm

a2b wrote:
AZS10Crew wrote:
a2b wrote: 50?
lord, he's only a bit off. i might add 15miles tops...how did you come up with 50?
Just a random number... It would increase the mileage though.

ooooohhhhhhhh
i thought you were bringin up the fact that he has 30's and that his odometer doesnt show all the miles he's actually putting on his truck

hold on here,with bigger tires and not reseting the speedo does that mean that my odometer isnt reading incorrectly,i know the speedometer is off,but i didint think it would affect the odometer

Jim · Post by **Jim** » Tue Oct 14, 2003 12:57 pm

melloyellow wrote:
a2b wrote:sounds right, you got 3.73 gears?
try a lighter foot and not going over 55mph
Without the above is their any way to increase the milage on these trucks? I would like to force it up to 20mpg.

Tail Wind

Crew02 · Post by **Crew02** » Tue Oct 14, 2003 4:35 pm

Yes, if one is off, they both are off.

KYLE · Post by **KYLE** » Wed Oct 15, 2003 1:30 am

What grade gas are you using? i have 3.73s too, and run 91 octane gas and get 300 miles a tank on average!

KYLE · Post by **KYLE** » Wed Oct 15, 2003 1:32 am

Crew02 wrote: Yes, if one is off, they both are off.

He's right bigger tires makes for less miles.

smokinjoe · Post by **smokinjoe** » Wed Oct 15, 2003 3:31 pm

i can see how speedo will be off but distance doesnt change

and i have 3.42 i must be maniac then when it comes to driving

adrenalnjunky · Post by **adrenalnjunky** » Wed Oct 15, 2003 3:56 pm

Lol --sorry

Your truck doesnt use GPS to measure distance -- that mans that it has to gauge the distance traveled from the speed that the tire reports.

Lets say your stock tire rolls 4 feet forward for every one revolution of your axle. (I'm making that 4 feet figure up.)

your truck is programmed to know that that one revolution equals 4 feet forward in distance. so that way your truck's computer can count the # of revolutions of that axle and tell you how fast you are going, and how far you have gone. Speedometer and odometer are calibrated and all is well with the world.

Now you move up to a 31 inch tire from your stocker 28's. A larger circumference means the tire will cover more ground in one full turn of the axle. Lets suppose now one full turn of the axle covers 6 feet.

Without recalibrating, your truck has no idea how far forward it went, all it knows is that your axle turned over one turn, so it thinks you went 4 feet, when you really went 6.

1 mile = 5280 feet. 5280 / 4 = 1320 -- this means your truck knows that if that axle rotates 1320 time , that it has covered 1 mile. The computer in your truck tells the odometer to add one mile every 1320 rotations of the axle.

The problem is that with your 31 on your truck actually covers more ground in those 1320 roations. 1320 * 6 = 7920 feet traveled, or 2640 extra feet (Half a mile), when the truck thinks it has only gone 1 mile.

If these numbers were true -- and I bet they're not too far off -- then that would mean if you drove 300 miles by your odometer on the bigger tire, you will actually have covered 450 miles distance.

Clear as mud?

AZS10Crew · Post by **AZS10Crew** » Wed Oct 15, 2003 3:58 pm

Distance does change. For example...when the speedo shows 80 mph, but you're actually going 85, that means in an hour you'll travel 85 miles...but your truck thinks you only went 80 miles in that hour. The truck bases the speedometer and odometer on revs in the tranny (or is it engine?). A certain number of revs used to take you a certain distance, but when you put on bigger tires (meaning greater circumferance...meaning greater distance traveled with each revolution) that same number of revs is taking you a greater distance. That means your odometer is reading less miles than the truck is actually traveling. That's why the computer needs to be recalibrated for different tire diameters.

Edit: Duplicate posts.

adrenalnjunky · Post by **adrenalnjunky** » Wed Oct 15, 2003 4:18 pm

Ok--so I did the math -- results werent as drastic as my example,

But a 28 inch 235/70/15 has a circumference of 7.33ft - the 3's is 8.11 feet for a 9.4 inch or .78 foot difference per revolution

this means if you drive a distance that is geographically 100 miles apart without recalibrating from a 28 to a 31, your odometer should tell you you only went 78 miles.

At least that's the figures I come up with -- I never was a math geek.

melloyellow · Post by **melloyellow** » Wed Oct 15, 2003 4:38 pm

I have done the HyperTech upgrade so my speedometer is correct. I get 15 mpg in the city and about 18 mpg on the highway. I would like to find ways to boost that up. I would be excited to see 18 and 20 instead.

Crew02 · Post by **Crew02** » Wed Oct 15, 2003 5:09 pm

I would have thought you have gotten better than 18 mpg with that lid. Have you checked it since it was installed? Also, I run 93 all of the time. I'm on a car allowance from work and they pay for all of my gas.

Just wondering? , what altitude do you run at? I was just wondering because I have a friend that I work with who drives a Dakota CC. We were down in Houston TX working a few weeks ago and he had driven down from Denver. He was really stoked because his truck had alot more power in the lower altitude and his gas mileage increased. He said that when he gets into the higher altitudes the power loss is noticeable.

melloyellow · Post by **melloyellow** » Wed Oct 15, 2003 7:18 pm

Crew02 wrote:I would have thought you have gotten better than 18 mpg with that lid. Have you checked it since it was installed? Also, I run 93 all of the time. I'm on a car allowance from work and they pay for all of my gas.

Just wondering? , what altitude do you run at? I was just wondering because I have a friend that I work with who drives a Dakota CC. We were down in Houston TX working a few weeks ago and he had driven down from Denver. He was really stoked because his truck had alot more power in the lower altitude and his gas mileage increased. He said that when he gets into the higher altitudes the power loss is noticeable.

I run at about 100 feet above sea level. That is with the lid and all mods listed to date. Filled up on Saturday and then on Monday. Do a lot of running on the weekends.

a2b · Post by **a2b** » Wed Oct 15, 2003 8:02 pm

ya the wheather plays a big role as well...humidty, heat, altitude....ask and drag racing geek....

i bet brule has his own barometer and wheather station statalite hookup to some sort of laptop thingy when he goes to the track

Post by **HenryJ** » Wed Oct 15, 2003 9:20 pm

a2b wrote:...ask any drag racing geek....

i bet brule has his own barometer and wheather station statalite hookup to some sort of laptop thingy when he goes to the track

I do have an air density gauge, altimeter, barometer, humidity, temperature, and wind speed gauges at the track with me, but mostly used a Casio Pathfinder watch and the flag on the timing tower

AZS10Crew · Post by **AZS10Crew** » Wed Oct 15, 2003 10:01 pm

HenryJ wrote:
a2b wrote:...ask any drag racing geek....

i bet brule has his own barometer and wheather station statalite hookup to some sort of laptop thingy when he goes to the track
I do have an air density gauge, altimeter, barometer, humidity, temperature, and wind speed gauges at the track with me, but mostly used a Casio Pathfinder watch and the flag on the timing tower

Post by **HenryJ** » Thu Oct 16, 2003 4:58 am

I usually figure that my HenryJ runs about .1 sec for every 1000 ft drop in adjusted altitude.

Denser air contains more oxygen , allowing for more fuel to be burned, which creates more power.

a2b · Post by **a2b** » Thu Oct 16, 2003 9:04 am

HenryJ wrote:I usually figure that my HenryJ runs about .1 sec for every 1000 ft drop in adjusted altitude.

Denser air contains more oxygen , allowing for more fuel to be burned, which creates more power.

wow...

so down in louisiana, i just go by the beads of sweat on my face. if i have 2, then humidity is around 70, 3, 80...and so forth...a full 100percent humidity will slow down the car a good 1/2 second sometimes...