The Adventures of Sylvester, the 2018 Suburban 3500 HD and our 2017 Airstream 27FB

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Fless

Staff member
Moderator
Joined
Apr 2, 2017
Posts
16,397
Reaction score
33,914
Location
People's Republic of Colorado
Etrailer has a mounting box with a worm gear clamp, for one:


It mounts somewhat sideways so doesn't hang down.

1742175515341.png
 
OP
OP
Geotrash

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
7,845
Reaction score
20,404
Location
Richmond, VA
I wonder if there's a way to monitor both fuel tank levels via PIDs with a scanner. Maybe graph them over time to see if there are glitches or other weirdness (technically speaking...)
So, I finally had a moment to consult Alldata, and here are a few clues. I don't yet have a scanner that can read these (haven't tried them all yet though), so I don't know if I can monitor the PIDs. But I suspect based on the information here, that the higher fuel consumption while towing caused too great of a discrepancy between the front and rear tank fuel level senders, such that the computer switched the fuel gauge off rather than risk displaying what it calculated would be inaccurate readings. I didn't check for stored codes so this is only a guess at this point. But per below, setting the fuel gauge to zero and illuminating the low fuel light is the expected behavior when a fault is detected, so the only thing that doesn't fit is that my low fuel light never illuminated.

1742215926193.png

1742215986020.png
 
OP
OP
Geotrash

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
7,845
Reaction score
20,404
Location
Richmond, VA
Sold the factory wheels and tires on FB marketplace today for an easy $500. A guy came up from Louisa and snatched them up with cash - only had them listed for 12 hours. I had them advertised for $600 and told him that was the price until we meet in person. Nice guy, both of us commented on how grateful we were to have a good experience on that cesspool of a site.

1742496628788.png

1742496677621.png

1742496707283.png
 

petethepug

Michael
Joined
May 4, 2016
Posts
3,788
Reaction score
4,356
Location
SoCal
Ah yes, photographic evidence of the value of the 2nd row bench seat.

IMG_3068.jpeg


In our 08 YXL Denali on long trips my wife and I would be talking and then we’d hear the DVD end with total silence. A look back would be exactly what you pictured. Awesomeness!
 

adventurenali92

Full Access Member
Joined
Feb 16, 2015
Posts
7,722
Reaction score
9,173
Location
Big Bear Lake, ca
Sold the factory wheels and tires on FB marketplace today for an easy $500. A guy came up from Louisa and snatched them up with cash - only had them listed for 12 hours. I had them advertised for $600 and told him that was the price until we meet in person. Nice guy, both of us commented on how grateful we were to have a good experience on that cesspool of a site.
Little return on the new wheel and tire setup is always good haha. Nicely done!
 
OP
OP
Geotrash

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
7,845
Reaction score
20,404
Location
Richmond, VA
Ah yes, photographic evidence of the value of the 2nd row bench seat.

View attachment 452967

In our 08 YXL Denali on long trips my wife and I would be talking and then we’d hear the DVD end with total silence. A look back would be exactly what you pictured. Awesomeness!
Yes indeed! And there’s a large dog back there somewhere too.
 

B-train

Full Access Member
Joined
Sep 12, 2022
Posts
2,709
Reaction score
4,914
For the short time I had a Denali XL I loved it for road trips. All the extra room behind the rear seats was fantastic. And.......the extra exhaust growl that the XL has over the standard wheelbase is a plus too. My mom was riding in the back on a trip to FL and even commented on how nice it sounds. LOL!

However, that was it's last voyage due to excessive oil consumption, and where it was traded for our current 2017. I'd do another XL or ESV for sure if that need arises. With the factory suspension working as it should, it's basically like driving your living room down the road.......
 
OP
OP
Geotrash

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
7,845
Reaction score
20,404
Location
Richmond, VA
For the short time I had a Denali XL I loved it for road trips. All the extra room behind the rear seats was fantastic. And.......the extra exhaust growl that the XL has over the standard wheelbase is a plus too. My mom was riding in the back on a trip to FL and even commented on how nice it sounds. LOL!

However, that was it's last voyage due to excessive oil consumption, and where it was traded for our current 2017. I'd do another XL or ESV for sure if that need arises. With the factory suspension working as it should, it's basically like driving your living room down the road.......
Your mama sounds like she’s an appreciator of fine automobiles! My wife absolutely loves the sound of both of our Denali‘s. Every time we fire it up and that exhaust barks for a second, she smiles. The Suburban 3500 actually has a similar exhaust system so it sounds good too. Not quite as aggressive but it’s satisfying nonetheless
 
OP
OP
Geotrash

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
7,845
Reaction score
20,404
Location
Richmond, VA
Got the Denali cluster installed today.

Before:
img_2767-jpeg.jpg


After:
img_2788-jpeg.jpg


img_2771-jpeg.jpg


Mileage came over correctly. However I haven’t been able to get Apple Maps to work on the navigation screen via either wired (direct) or wireless CarPlay (with adapter). Album art comes over but the playlist names don’t. Seems to get more data the longer it’s connected and running so we’ll see if anything changes on our next trip.

I did not install the HUD gear yet.

One thing I love: tow/haul mode displays the transmission temperature in place of voltage.
 
OP
OP
Geotrash

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
7,845
Reaction score
20,404
Location
Richmond, VA
She's been sitting in the garage waiting on our first camping trip of the season in a few weeks. Oil life minder was down to 28% after 9 months and 3,000 miles of driving so I did an oil change in the driveway today. Pennzoil Platinum synthetic 5w-30 and a Wix 57060 oil filter. Easy peasy. The old oil came out pretty clean - a dark amber in color.

It was the first time I'd had it up on ramps and laid underneath it, but it's really clean under there, having never seen salt. Going to try to keep preserving this one for the decades ahead.

1745252292584.png
 

1TONSUB

TYF Newbie
Joined
May 27, 2025
Posts
21
Reaction score
41
Location
Wisconsin
Dave absolutely beautiful rig. Surprising how low they actually are and ramps needed to get under. Its mostly the low front air dam, which are pretty robust as I discovered on a overlanding trip sometime ago.
 
OP
OP
Geotrash

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
7,845
Reaction score
20,404
Location
Richmond, VA
Dave absolutely beautiful rig. Surprising how low they actually are and ramps needed to get under. Its mostly the low front air dam, which are pretty robust as I discovered on a overlanding trip sometime ago.
Thank you, Kevin! I note you have great taste in paint color and wheels, too!
 

1TONSUB

TYF Newbie
Joined
May 27, 2025
Posts
21
Reaction score
41
Location
Wisconsin
Oddly enough, my truck did the same thing with the gas gauge recently. Then as quick as it stopped working it came back to life?

I daily drive mine and then road trip with 3-4 ppl + large dog.
Daily avg = 13-14ish (usually around 13.5)
Highway… depends. <70mph = 15-16
>70 = 14-15
Wow must be a thing mine did that on a long drive to yellow stone. Filled up drove about an hour then gas gauge went to Zero. I freaked pulled into next fuel station looked for leaks and such. Put a few gallons in then started up and all normal. Never happened again. On a related note lets talk about fill ups.

I have never ever been able to put more than 25-30 gal in mine. I also have never run under 1/4 tank. Maybe all extra capacity is from E to 1/4?

Also never fill up when running as it messes up gauge reading supposedly.
 

Bigburb3500

Full Access Member
Joined
Jun 7, 2024
Posts
852
Reaction score
1,335
Wow must be a thing mine did that on a long drive to yellow stone. Filled up drove about an hour then gas gauge went to Zero. I freaked pulled into next fuel station looked for leaks and such. Put a few gallons in then started up and all normal. Never happened again. On a related note lets talk about fill ups.

I have never ever been able to put more than 25-30 gal in mine. I also have never run under 1/4 tank. Maybe all extra capacity is from E to 1/4?

Also never fill up when running as it messes up gauge reading supposedly.
I regularly put 32-34gal in my truck. I don’t intentionally run it to E but life happens and we have a regular roadtrip that I drive straight from NC—>OH with no fill-ups because prices get high in WV and Southern OH.
 
OP
OP
Geotrash

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
7,845
Reaction score
20,404
Location
Richmond, VA
Wow must be a thing mine did that on a long drive to yellow stone. Filled up drove about an hour then gas gauge went to Zero. I freaked pulled into next fuel station looked for leaks and such. Put a few gallons in then started up and all normal. Never happened again. On a related note lets talk about fill ups.

I have never ever been able to put more than 25-30 gal in mine. I also have never run under 1/4 tank. Maybe all extra capacity is from E to 1/4?

Also never fill up when running as it messes up gauge reading supposedly.
The fill capacity illusion is an issue on the 1500's as well. Both of my XL Denali's have a 31 gallon tank but I've never been able to put more than 26 gallons in either of them - and that was when I was sweating bullets after driving longer than I was planning to with the fuel light on, and the DTE display showing 2 miles to empty. Everyone else I've seen write about it is having similar experiences. So I'm not surprised that it's even more pronounced with the larger fuel capacity spread over 2 tanks. Anyone wanna be the guinea pig to see how far she'll go below "E"?

I'd be in deep shit with my wife if we had a carful of kids, pulling a trailer, and ran out of gas. At least it wouldn't be as embarrassing as running out of gas in, say, a Prius.
 

1TONSUB

TYF Newbie
Joined
May 27, 2025
Posts
21
Reaction score
41
Location
Wisconsin
The fill capacity illusion is an issue on the 1500's as well. Both of my XL Denali's have a 31 gallon tank but I've never been able to put more than 26 gallons in either of them - and that was when I was sweating bullets after driving longer than I was planning to with the fuel light on, and the DTE display showing 2 miles to empty. Everyone else I've seen write about it is having similar experiences. So I'm not surprised that it's even more pronounced with the larger fuel capacity spread over 2 tanks. Anyone wanna be the guinea pig to see how far she'll go below "E"?

I'd be in deep shit with my wife if we had a carful of kids, pulling a trailer, and ran out of gas. At least it wouldn't be as embarrassing as running out of gas in, say, a Prius.
Good to hear. Guess as a Wisconsin native its coded to my brain to not go bellow 1/4 tank. I might try the test as I am curious. Like you I always have mission critical cargo on board and can't be fing around testing :). Maybe will try to drive to work for while and keep a 5 gal jerry can in the back.

I am still learning about the operation of the dual tanks. I will drop this here for reference. https://www.tahoeyukonforum.com/threads/can-someone-explain-the-dual-fuel-tank-set-up-i-have.133271/
 
Last edited:

Bigburb3500

Full Access Member
Joined
Jun 7, 2024
Posts
852
Reaction score
1,335
Good to hear. Guess as a Wisconsin native its coded to my brain to not go bellow 1/4 tank. I might try the test as I am curious. Like you I always have mission critical cargo on board and can't be fing around testing :). Maybe will try to drive to work for while and keep a 5 gal jerry can in the back.

I am still learning about the operation of the dual tanks. I will drop this here for reference. https://www.tahoeyukonforum.com/threads/can-someone-explain-the-dual-fuel-tank-set-up-i-have.133271/
IMG_8392.jpeg

35.3 gallons…. Is this verification enough we have 36 gallons of fuel onboard?
 

adventurenali92

Full Access Member
Joined
Feb 16, 2015
Posts
7,722
Reaction score
9,173
Location
Big Bear Lake, ca
The fill capacity illusion is an issue on the 1500's as well. Both of my XL Denali's have a 31 gallon tank but I've never been able to put more than 26 gallons in either of them - and that was when I was sweating bullets after driving longer than I was planning to with the fuel light on, and the DTE display showing 2 miles to empty. Everyone else I've seen write about it is having similar experiences. So I'm not surprised that it's even more pronounced with the larger fuel capacity spread over 2 tanks. Anyone wanna be the guinea pig to see how far she'll go below "E"?

I'd be in deep shit with my wife if we had a carful of kids, pulling a trailer, and ran out of gas. At least it wouldn't be as embarrassing as running out of gas in, say, a Prius.
Yup my 1500 Denali has the same issue. Have never been able to put a full 30 gallons in it….. but I also absolutely refuse to let it go below a quarter tank either. And I’ve never ran out of fuel and been stuck with my Denali lol.
 

Forum statistics

Threads
137,809
Posts
1,992,699
Members
102,794
Latest member
Drewphil
Back
Top