800 miles, 1 day, some learnings

[Protect1989]

Wife and I just completed an 800 mile, 12 hour drive in our 2 week old, 2026 Tahoe Z71 with the 5.3L. Here are some initial learnings

- MPG: We ended up getting between 19-21MPG at 77mph. Each tank lasted roughly 400 miles

- Ride Quality: The air suspension is incredible. Remarkably smooth ride and did a great job handling the less than ideal highways through Louisiana. Highly recommend air suspension for those on the fence.

- Wind Noise: it was a particular windy day on this drive but I was noticing a bit of wind noise on the drivers side. Not sure if there is a seal askew, the mirrors just make wind noise, or it was a fluke of the day

- Seats: this one is going to be subjective. I’m having a hard time getting comfortable. Specifically in my thighs. It’s as though the seat is hitting a pressure point or the seat cushion isn’t long enough. I need to figure out a solution because this is a big problem.

- Navigation: we used Waze the entire trip and changed the center display to show the map (which shows Waze, an amazing feature). However, on the instrument cluster Waze leaves a giant icon in the center about your next turn, even if that next turn is hundreds of miles away, blocking the navigation map. This is a UI annoyance and hopefully will be fixed via update.

 

[RST Dana]

Fuel mileage manual calculations or WAG based on the guess provided by your ride? The only true way to determine absolutely correct mileage is manual logs/data. I have been checking all of my rides for the last 8 years and NO vehicle has been accurate every time. Sometimes high and sometimes low.

 

[Protect1989]

Just the onboard computer. Wasn’t concerned enough about it to do manual calculations. More of a curiosity

 

[RST Dana]

Just the onboard computer. Wasn’t concerned enough about it to do manual calculations. More of a curiosity

Well, when mine was saying over 23, I started checking. Most times, highway on cruise is actually better than reported. City can be sometimes a tad less.

 

[Joseph Garcia]

Sounds like you have a winner there. Hopefully, you will get the seat adjustment to work for you.

Thank you for sharing your experience. Our collective knowledge base for a new model has been increased.

 

[Marky Dissod]

this one is going to be subjective. I’m having a hard time getting comfortable. Specifically in my thighs.
It’s as though the seat is hitting a pressure point or the seat cushion isn’t long enough. I need to figure out a solution because this is a big problem.

TRY lowering the front while keeping the middle & rear higher.
If it has an adjustment to move the tushion forward relative to the backrest, find it.

 

[TrueAt1stLight]

Pro tip: if you have an iPhone (may work the same for Android but I wouldn’t know): set Apple Maps to navigate to your destination via CarPlay then once it’s live and showing in your HUD, switch your infotainment view to Waze to monitor for police presence but not nav directions, as I don’t believe Waze will
show directions in the HUD.

Also buy and mount up high a Valentine V1, for… reasons.

 

[Imalabil]

I also put a ton of miles on my 2026 Tahoe RST. It had 3 delivery miles on it on Dec 6 and over 2,500 a week and a half later. I varied rpm using the L range for the first 1k miles or so. A great cruiser. Also had the dealer change the oil as soon as I returned.
I missed the space in my 2002 Suburban and it's good to be back! Mileage was between 14.8 and 22 based on the in-car computer. Found out is does need front splash guards - winter snow/slush kicks up from the front tires and makes the running boards slippery. In the garage waiting to go on.

 

[Protect1989]

Just wrapped up my trip. In total put on roughly 1800 miles in one week. Two things I was surprised about

- I still can not get comfortable in the seat. For some reason the side bolster or length of the bottom cushion dig into my thighs and cause pain. Never had this happen before and certainly did not have this issue in my 22 sierra. I’m guessing it’s cause the seats are softer? I don’t know

- best MPG I achieved was 17.3. Had ACC set to 75, no stop*go traffic, 2 adults, 2 dogs, moderate to light luggage. I know this isn’t a Prius but was hoping to be in the 20s

 

[JayceeP]

Just wrapped up my trip. In total put on roughly 1800 miles in one week. Two things I was surprised about

- I still can not get comfortable in the seat. For some reason the side bolster or length of the bottom cushion dig into my thighs and cause pain. Never had this happen before and certainly did not have this issue in my 22 sierra. I’m guessing it’s cause the seats are softer? I don’t know

- best MPG I achieved was 17.3. Had ACC set to 75, no stop*go traffic, 2 adults, 2 dogs, moderate to light luggage. I know this isn’t a Prius but was hoping to be in the 20s

17.3 doesn’t seem great, but could depend on your elevations and weather. What was your start and end destination area. Hilly highways or mostly flat? Though technically speaking the 6.2 is only rated for nominally better on the highway…. However you do see claims of 20+mpg. Again, I asssume this is deadly highway conditions.

I can pretty much bank on 24-25 in my ‘24 Yukon XL 3.0 diesel in that 75-80mph range. Somewhat hilly highways however. 26 is realistic but I don’t quite see it that good very often. Again, speed and highway conditions greatly matter. Cold and Snowy/messy conditions can easily drop it to 20-21mpg on that same stretch.

 

[ReaperHWK]

17.3 doesn’t seem great, but could depend on your elevations and weather. What was your start and end destination area. Hilly highways or mostly flat? Though technically speaking the 6.2 is only rated for nominally better on the highway…. However you do see claims of 20+mpg. Again, I asssume this is deadly highway conditions.

I can pretty much bank on 24-25 in my ‘24 Yukon XL 3.0 diesel in that 75-80mph range. Somewhat hilly highways however. 26 is realistic but I don’t quite see it that good very often. Again, speed and highway conditions greatly matter. Cold and Snowy/messy conditions can easily drop it to 20-21mpg on that same stretch.

You ever calculate with the added cost of the diesel fuel does it still actually save money on gas? I didn’t see a huge savings because your paying more for the actual diesel.

 

[2024 White Tahoe]

You ever calculate with the added cost of the diesel fuel does it still actually save money on gas? I didn’t see a huge savings because your paying more for the actual diesel.

+ DEF fluid.

 

[JayceeP]

+ DEF fluid.

DEF fluid is a rip off in Canada but I go through 3 jugs per year. So even at rip off prices that’s $90/year. $60 if I get the Walmart stuff.


That cost alone is worth the 1,000km/600mile range my gauge shows every time I fill up when on road trips.

 

[JayceeP]

You ever calculate with the added cost of the diesel fuel does it still actually save money on gas? I didn’t see a huge savings because your paying more for the actual diesel.

I don’t drive a ton but overall I’m thumbing it somewhere around $1,000/year savings including the little bit of DEF fluid.

I feel like that 6.2 is going to be worse than the EPA stated numbers around town. But if I assume bad numbers on both ie the 14.5mpg on the 6.2 and 20mpg on the diesel the diesel is getting 37% more range. That number holds true if I used highway MPG too.

Where I live, diesel is about 12-15% more than Premium.

So, still decent and that becomes more meaningful if you drive a lot. I’m mathing around 20%-25% max savings on fuel. Probably around $800-$1000/year for me if I drive a decent amount.

 

[Tinman265]

I don’t drive a ton but overall I’m thumbing it somewhere around $1,000/year savings including the little bit of DEF fluid.

I feel like that 6.2 is going to be worse than the EPA stated numbers around town. But if I assume bad numbers on both ie the 14.5mpg on the 6.2 and 20mpg on the diesel the diesel is getting 37% more range. That number holds true if I used highway MPG too.

Where I live, diesel is about 12-15% more than Premium.

So, still decent and that becomes more meaningful if you drive a lot. I’m mathing around 20%-25% max savings on fuel. Probably around $800-$1000/year for me if I drive a decent amount.

If you run premium in the 6.2 like it wants then the savings of the diesel is a no brainer if you drive enough for proper regeneration cycles. If your running around town and don't have a way to let the regen complete fully buying the diesel is not a good idea.

For comparison we did 5200 miles in 14 days and averaged 18.2. $1100 in fuel for the trip. Around town the 6.2 is a hog. I came from a 5.3 where 21-22 was the average but my Yukon is not a daily driver.

 

[Protect1989]

My old diesel would easily do 26mpg on the highway, giving around 600 miles of range. It was a beast and realistically I should have gotten the diesel on my Tahoe.

However diesel is currently about $1/gallon more. So each tank is roughly $20 more with the diesel. The range can not be beat though.

I don’t know why my 5.3 got such garbage mileage this trip. Georgia to texas is relatively flat. Maybes it’s just breaking in (started at 300 miles, ended at 2000+), maybe it needs an oil change, who knows.

 

[JayceeP]

If you run premium in the 6.2 like it wants then the savings of the diesel is a no brainer if you drive enough for proper regeneration cycles. If your running around town and don't have a way to let the regen complete fully buying the diesel is not a good idea.

For comparison we did 5200 miles in 14 days and averaged 18.2. $1100 in fuel for the trip. Around town the 6.2 is a hog. I came from a 5.3 where 21-22 was the average but my Yukon is not a daily driver.

I somewhat often don’t complete regents. My worst tank in nearly 13,000miles is just under 20mpg - 19.6 to be exact. Most tanks are closer 21mpg for day-to-day which for me is light suburban driving and shortish highway trips of 20mins or less.

When I hit the highway for an hour or more, 25mpg here I come lol.

One thing with the diesel is the fuel economy reading is always bang on to the hand calculated number. Never off by more than 1-2%.

Unless you’re in stop and go city driving on the regular this thing really doesn’t want to burn much worse than 20 mpg….