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swathdiver

swathdiver

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Sick again with an awful cough, can't lay down so I might as well read the shop manual right? Well, here's some nuggets that might be helpful or interesting to folks over time:

GMT900 SUVs

26 Gallon Tank - Tahoe, Yukon & Escalade

E - 0 to 3.1 Gallons
1/4 - 8.7 Gallons
1/2 - 13.5 Gallons
3/4 - 19.7 Gallons
F - 24.5-25.9 Gallons
Low Fuel Light On - 4.3 Gallons
Low Fuel Light Off - 5 Gallons

31 Gallon Tank - Suburban, Avalanche, Yukon XL, Escalade ESV & Escalade EXT

E - 0 to 4 Gallons
1/4 - 11 Gallons
1/2 - 18 Gallons
3/4 - 23.5 Gallons
F - 29.4-30.9 Gallons
Low Fuel Light On - 3.8 Gallons
Low Fuel Light Off - 5.1 Gallons

37 Gallon Tanks - 2500 Suburban & Yukon XL

E - 5 Gallons
1/4 - 11.4 Gallons
1/2 - 18.5 Gallons
3/4 - 24.7 Gallons
F - 35-37 Gallons
Low Fuel Light On - 7.5 Gallons
Low Fuel Light Off - 8 Gallons

Some literature says the 31 gallon tank is 31.5 gallons. My Tech2 says it is 31.2 gallons. I wonder if there's room on a 1500s frame above the spare tire to put the 2500s 11.5 Gallon second fuel tank up there? Sure would make the ride smoother when the truck is empty.
 
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PG01

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Sick again with an awful cough, can't lay down so I might as well read the shop manual right? Well, here's some nuggets that might be helpful or interesting to folks over time:

GMT900 SUVs

26 Gallon Tank

E - 0 to 3.1 Gallons
1/4 - 8.7 Gallons
1/2 - 13.5 Gallons
3/4 - 19.7 Gallons
F - 24.5-25.9 Gallons
Low Fuel Light On - 4.3 Gallons
Low Fuel Light Off - 5 Gallons

31 Gallon Tank

E - 0 to 4 Gallons
1/4 - 11 Gallons
1/2 - 18 Gallons
3/4 - 23.5 Gallons
F - 29.4-30.9 Gallons
Low Fuel Light On - 3.8 Gallons
Low Fuel Light Off - 5.1 Gallons

37 Gallon Tanks

E - 5 Gallons
1/4 - 11.4 Gallons
1/2 - 18.5 Gallons
3/4 - 24.7 Gallons
F - 35-37 Gallons
Low Fuel Light On - 7.5 Gallons
Low Fuel Light Off - 8 Gallons

Some literature says the 31 gallon tank is 31.5 gallons. My Tech2 says it is 31.2 gallons. I wonder if there's room on a 1500s frame above the spare tire to put the 2500s 11.5 Gallon second fuel tank up there? Sure would make the ride smoother when the truck is empty.
Good to know since i ran mine out of gas 2x.... 35 miles to empty b.s.
 

kbuskill

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Sick again with an awful cough, can't lay down so I might as well read the shop manual right? Well, here's some nuggets that might be helpful or interesting to folks over time:

GMT900 SUVs

26 Gallon Tank

E - 0 to 3.1 Gallons
1/4 - 8.7 Gallons
1/2 - 13.5 Gallons
3/4 - 19.7 Gallons
F - 24.5-25.9 Gallons
Low Fuel Light On - 4.3 Gallons
Low Fuel Light Off - 5 Gallons

31 Gallon Tank

E - 0 to 4 Gallons
1/4 - 11 Gallons
1/2 - 18 Gallons
3/4 - 23.5 Gallons
F - 29.4-30.9 Gallons
Low Fuel Light On - 3.8 Gallons
Low Fuel Light Off - 5.1 Gallons

37 Gallon Tanks

E - 5 Gallons
1/4 - 11.4 Gallons
1/2 - 18.5 Gallons
3/4 - 24.7 Gallons
F - 35-37 Gallons
Low Fuel Light On - 7.5 Gallons
Low Fuel Light Off - 8 Gallons

Some literature says the 31 gallon tank is 31.5 gallons. My Tech2 says it is 31.2 gallons. I wonder if there's room on a 1500s frame above the spare tire to put the 2500s 11.5 Gallon second fuel tank up there? Sure would make the ride smoother when the truck is empty.

Good info... so here is my question.

I assume the 26 gallon tank is for the Tahoe.

I am 99% sure my Suburban has the 31 gallon tank.

So what gets the 37 gallon tank?

I'm guessing maybe the 2500's?
 
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swathdiver

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So what gets the 37 gallon tank?

I'm guessing maybe the 2500's?

I think so, yes. I think it's the 26 and an 11 gallon reserve.

Right, the 2500s have two tanks, each with their own pump and sending units. They drain concurrently or nearly so I think. Wonder why GM chose not to use the 31 gallon tank up front? The GMT400s had a 42 gallon fuel capacity.
 
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swathdiver

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For those with twin electric fans:

The ECM commands the low speed setting ON under these conditions:

- ECT reaches about 202 degrees.
- AC Pressure exceeds 210 PSI
- After the engine shuts off, if the coolant is greater than 214 degrees the low speed fans will run for at least a minute. At the end of this minute, if the ECT drops below 214 the fans will shut off. They will shut off after 3 minutes regardless of temperature.

The ECM commands the high speed setting ON under these conditions:

- ECT exceeds 220 degrees
- AC Pressure exceeds 265 PSI
- When certain DTCs set.

While idling and at very low speeds, the fans are only allowed to speed up if required to maintain idle stability and keep them from cycling back and forth.
 
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swathdiver

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Just finished up the 7th consecutive tank of E85 from a local Sunoco. The last three tanks were at an alcohol content of 80% and we reran the mileage numbers compared to when we ran them last time when the alcohol content was 68 and 73 percent.

We drove almost 2,000 miles and averaged 12.04 mpg. The average price paid for fuel was $2.30 which worked out to $.19 cents a mile.

E85 @ 80% Alcohol Content MPG:

35 MPH = 16.5 MPG
40 MPH = 17 MPG
45 MPH = 18 MPG
50 MPH = 17 MPG
55 MPH = 16 MPG
60 MPH = 15 MPG
65 MPH = 15 MPG
70 MPH = 14 MPG
75 MPH = 13.6 MPG

Mileage rounded to the nearest whole number save for the two shown as they were in the middle. The others were within two tenths of a whole number. Most of these were derived from 2-way averages over the same stretch of road(s).
 
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swathdiver

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Just filled up with 2nd tank of Chevron 93. First tank was at 18% alcohol content and averaged 14.8 mpg with mixed driving. Refueled down south, same fuel, and headed home. After sixty some miles the alcohol content settled down to 7% and pulled into the driveway with an 18.5 mpg average. Highest ever. Truck was about 6900 pounds loaded.

Spent two days fooling with the tires after the tire store bungled the rotation. That busted bolt is starting to affect the wear pattern on the steer axle.

Still having trouble with my eyeballs, still hurts to look at the computer screen and my phone. Got to have the Doc check them out.
 

kbuskill

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Just filled up with 2nd tank of Chevron 93. First tank was at 18% alcohol content and averaged 14.8 mpg with mixed driving. Refueled down south, same fuel, and headed home. After sixty some miles the alcohol content settled down to 7% and pulled into the driveway with an 18.5 mpg average. Highest ever. Truck was about 6900 pounds loaded.

Spent two days fooling with the tires after the tire store bungled the rotation. That busted bolt is starting to affect the wear pattern on the steer axle.

Still having trouble with my eyeballs, still hurts to look at the computer screen and my phone. Got to have the Doc check them out.

Hope you get feeling better James.... eyes are kinda important... lol
 

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