Useless Information

[Teeroy78]

That's not bad Randy for the amount of power under your foot!

I was at 15.2 and climbing until an emergency run and idling dropped it into the 12s the last few days. Got back up to 13 or so and that's it so far. At least its better than it used to be.

Ohh, I signed up for that Fuelly App. Most of the GMT900 5.3 SUVs average 14-15 mpg between fills. The VVTs get about 1 mpg better and the 2009s all seem to average in the 14s with @Teeroy78 and me with historical averages in the 11 mpg range. I reckon he's on E85 or has had issues like me. Fuelly asks but does not publish what brands and octane ratings we're running. I think that categorizing those would allow for even better accuracy and expose crummy gas for all to see. Anyhow, the others rarely saw 17 or 18, even on trips; there's nine 2009 Yukon XLs.

Ah, yeah I stopped updating my Fuelly log because it was just depressing . I have never run E85 because it isn’t available in Canada (or at least not in Manitoba), possibly because it gets too cold here or maybe we don’t have the same incentives to use it so it’s not cost effective. Not sure, but I’ve only seen it in the States. I ran 100% 87 octane. Our choices here are 87/89/91.

That said, a lot of that mileage logged on Fuelly was when my ethanol composition calculations were messed up and so my truck *thought* I was using E85. That’s what led to me justifying the purchase of my beloved Tech 2.

Just going by the DIC, it got a touch better when I reset the fuel composition, but it still sucks . Runs like a dream now though, which is more important to me.

Disclaimer - I haven’t ready the whole thread yet, so I’m not sure what I’m replying to other than James tagging me

 

[swathdiver]

That's all Troy, that I signed up for Fuelly and saw you there. Run a couple tanks of 91 and watch your mileage go up. Pick Exxon Mobil or Chevron, not Shell or Costco.

Have you run a graph with your 4 O2 sensors to test your cats? That is what was killing my gas mileage, the cats.

 

[Ben Hinz]

That's all Troy, that I signed up for Fuelly and saw you there. Run a couple tanks of 91 and watch your mileage go up. Pick Exxon Mobil or Chevron, not Shell or Costco.

Have you run a graph with your 4 O2 sensors to test your cats? That is what was killing my gas mileage, the cats.

Could you elaborate on this a-bit? I think this might be my issue.

 

[swathdiver]

Could you elaborate on this a-bit? I think this might be my issue.

When I bought my truck Ben, it got good gas mileage on the way home and maybe for that first week or so afterwards. Then it began to slowly and noticeably get worse. Finally, the computer started throwing codes for a bad cat on one side and several months later the other. With my Tech2, I would clear the code and it would take a couple weeks to return, then every time it was driven. Finally replaced the Y-pipe and cats and the gas mileage has returned to normal.

With an advanced scan tool like the Tech2, one can graph a combination of sensors and record it to analyze it later. You'll see examples of this on some of the preceding pages of this thread. Of course, monitoring the different sensors can also uncover other problems as well.

What's going on with your motor and or gas mileage?

 

[swathdiver]

Tank is running down, averaging 14.3 mpg. Still lots of city driving and idling, this tank also included about an hour on the highway too. Still fuel to burn before the next fill up. I'm well pleased.

Anyone know the difference, if any, between Federal and California catalytic converters on our trucks?

Here's some useless information: I often read about other trucks in 2009 that had higher tow ratings than the Suburban/Yukon XL. Something didn't seem right so I plugged ALL their data into my excel towing calculator I made and came up with this:

All vehicles are 4x4s with towing package for maximum capacities.

2009 GMC Yukon XL:
GCWR = 14,000 pounds
GVWR = 7,400 pounds
Tow Rating: 7,900

2009 Ford Expedition EL:
GCWR = 15,000 pounds
GVWR = 7,720 pounds
Tow Rating = 8,700 pounds

2009 Toyota Sequoia SR5:
GCWR = 16,000 pounds
GVWR = 7,300 pounds
Tow Rating = 9,600 pounds

2009 Nissan Armada:
GCWR = 15,100 pounds
GVWR = 7,299 pounds
Tow Rating = 9,000 pounds

2009 Chevrolet Suburban 2500
GCWR = 16,000 pounds
GVWR = 8,600 pounds
Tow Rating = 9,300 pounds

My first test to see which could haul the most was to assume a hitch weight of 10% of the Trailer Weight and 100 additional pounds of rear cargo. Passengers and their cargo were calculated at 700 pounds.

Yukon XL = 6,600 pounds Trailer Weight. Forty pounds below GCWR and GVWR and Cargo Weight.
Expedition EL = 6,300 pounds Trailer Weight. 5 Pounds below GVWR and Cargo Weight.
Sequoia SR5 = 4,500 pounds Trailer Weight. Right at GVWR and Cargo Weight.
Armada = 6,500 pounds Trailer Weight. Eight pounds below GVWR and Cargo Weight.
Suburban 2500 = 7,800 pounds Trailer Weight. 71 pounds below GCWR.

In another example, the hitch weight was increased to 12.5% of Trailer Weight, 100 pounds of additional cargo over the rear axle and 400 pounds of passengers.

Yukon XL = 6,700 pounds Trailer Weight. 62 1/2 pounds below GCWR.
Expedition EL = 7,100 pounds Trailer Weight. 2 1/2 pounds below the Trailer Hitch Rating.
Sequoia SR5 = 6,000 pounds Trailer Weight. GVWR and Cargo Weight Rating met.
Armada = 7,200 pounds Trailer Weight. Trailer Hitch Rating met. 58 pounds below Cargo Weight Rating and GVWR.
Suburban 2500 = 7,900 pounds Trailer Weight. 63-1/2 pounds before GCWR and 12.5 pounds under the hitch capacity.


Toyota is the big liar, while its axles can handle high loads, the whole package cannot, it's a tank, like the Expedition EL. The Suburban/Yukon XL has a higher cargo capacity than all of them, it can haul more stuff internally, including people compared to the others. The Toyota weighs 6,050 pounds, the Expedition EL weighs 6,285 pounds when both are configured the same as my Yukon XL which weighs 5,901 pounds. The Armada is most similar in weight, 5,841 pounds, and capability but its ratings too are over-inflated.

In preparing this, I came across many posts across the internet by folks who bought these tow vehicles thinking they could haul those published figures, being ignorant of all the other considerations that must be taken into account. Lots of money wasted and dreams broken. Learn the math.

 

[Jason_S]

Tank is running down, averaging 14.3 mpg. Still lots of city driving and idling, this tank also included about an hour on the highway too. Still fuel to burn before the next fill up. I'm well pleased.

Anyone know the difference, if any, between Federal and California catalytic converters on our trucks?

Here's some useless information: I often read about other trucks in 2009 that had higher tow ratings than the Suburban/Yukon XL. Something didn't seem right so I plugged ALL their data into my excel towing calculator I made and came up with this:

All vehicles are 4x4s with towing package for maximum capacities.

2009 GMC Yukon XL:
GCWR = 14,000 pounds
GVWR = 7,400 pounds
Tow Rating: 7,900

2009 Ford Expedition EL:
GCWR = 15,000 pounds
GVWR = 7,720 pounds
Tow Rating = 8,700 pounds

2009 Toyota Sequoia SR5:
GCWR = 16,000 pounds
GVWR = 7,300 pounds
Tow Rating = 9,600 pounds

2009 Nissan Armada:
GCWR = 15,100 pounds
GVWR = 7,299 pounds
Tow Rating = 9,000 pounds

My first test to see which could haul the most was to assume a hitch weight of 10% of the Trailer Weight and 100 additional pounds of rear cargo. Passengers and their cargo were calculated at 700 pounds.

Yukon XL = 6,600 pounds Trailer Weight. Forty pounds below GCWR and GVWR and Cargo Weight.
Expedition EL = 6,300 pounds Trailer Weight. 5 Pounds below GVWR and Cargo Weight.
Sequoia SR5 = 4,500 pounds Trailer Weight. Right at GVWR and Cargo Weight.
Armada = 6,500 pounds Trailer Weight. Eight pounds below GVWR and Cargo Weight.

In another example, the hitch weight was increased to 12.5% of Trailer Weight, 100 pounds of additional cargo over the rear axle and 400 pounds of passengers.

Yukon XL = 6,700 pounds Trailer Weight. 62 1/2 pounds below GCWR.
Expedition EL = 7,100 pounds Trailer Weight. 2 1/2 pounds below the Trailer Hitch Rating.
Sequoia SR5 = 6,000 pounds Trailer Weight. GVWR and Cargo Weight Rating met.
Armada = 7,200 pounds Trailer Weight. Trailer Hitch Rating met. 58 pounds below Cargo Weight Rating and GVWR.


Toyota is the big liar, while its axles can handle high loads, the whole package cannot, it's a tank, like the Expedition EL. The Suburban/Yukon XL has a higher cargo capacity than all of them, it can haul more stuff internally, including people compared to the others. The Toyota weighs 6,050 pounds, the Expedition EL weighs 6,285 pounds when both are configured the same as my Yukon XL which weighs 5,901 pounds. The Armada is most similar in weight, 5,841 pounds, and capability but its ratings too are over-inflated.

In preparing this, I came across many posts across the internet by folks who bought these tow vehicles thinking they could haul those published figures, being ignorant of all the other considerations that must be taken into account. Lots of money wasted and dreams broken. Learn the math.

Interestingly, the Toyota has a higher tow rating (by 300#) than the Yukon XL 2500 / Suburban 2500 and the Nissan is just 300# under.

 

[swathdiver]

Thought about this some more and pondered the thinking of Toyota.

So for this example, there's no additional weight, just a skinny 150 pound driver and 10% hitch weight.

Yukon XL = 7,200 pound Trailer. Thirty pounds under GCWR.
Expedition EL = 7,700 pound Trailer. Ninety-Five pounds under GCWR.
Sequoia SR5 = 8,900 pound Trailer. Ten pounds under GCWR.
Armada = 8,100 pound Trailer. Ninety-Nine pounds under GCWR.
Suburban 2500 = 8,400 pound Trailer. Sixty-One pounds under GCWR.

Hardly practical unless you have a ferry business or are single!

 

[swathdiver]

Interestingly, the Toyota has a higher tow rating (by 300#) than the Yukon XL 2500 / Suburban 2500 and the Nissan is just 300# under.

They do but when it comes to a realistic load, we'll have to see. Let me plug in the 2500 to this and see...

 

[swathdiver]

Ok, earlier posts amended to add the 2500 Suburban.

In the Ferrying example the Suburban 2500s tow capacity is exceeded by the Sequoia SR5s. However, the Suburban 2500 is not even close to running up against its others limits whereas in seventy pounds the Sequoia would limit out because its tow hitch limitation.

I reckon from talking to folks on this forum that the 2500 can easily haul more than that with the only fear of something breaking is the law.

 

[Jason_S]

Don't forget the Suburban holds about 13 gallons of fuel more than the Toyota and I think 11 more than the Nissan. That will factor both in weight and range.

I haven't pushed the limits on my 2500 like I did on my Tahoe, but that's the main reason that I went to the 2500. I think that if I were going to run the 2500 closer to it's max and more often, I would probably opt for a 2500HD PU with Duramax. Even with a slightly higher fuel cost, the Duramax would be a bit more efficient under load.