petethepug
Michael
A new 5.3L V8 with a 10 SP, direct injection, DFM, running on adaptive cruse and 17.5 mpg on Reg fuel isn’t bad at all. Not sure what rims and tires you’re running or how hard a/c was working.
Bad mpg?
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blanchard7684
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I'm 5000 miles into a '24 suburban z71 with 5.3. I'm not focused on fuel mileage in general. However in testing difference between DFM and DFM disabled (L9) is noticed only about a 1 mpg difference with DFM engaged.
Where I drive it is alot of 75 mph highway, wind, and frequently a lot of hills.
I'm getting 17.5 mpg on average.
The window sticker values don't really reflect real world (75 mph speed limit) driving.
When I go 65 mph for appreciable amount of time I can easily meet and usually exceed the window sticker values.
Where I drive it is alot of 75 mph highway, wind, and frequently a lot of hills.
I'm getting 17.5 mpg on average.
The window sticker values don't really reflect real world (75 mph speed limit) driving.
When I go 65 mph for appreciable amount of time I can easily meet and usually exceed the window sticker values.
Marky Dissod
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I find it interesting that, after decades of Corporate Average Fuel Economy testing,
leading from 3-speed to 10-speed transmissions and myriad technologies for improving MpGs,
'they' have never bothered to state a road speed range where a given vehicle gets near its best MpGs.
Whatever the 'city' MpG' cited by the Monroney sticker, it ain't easy to achieve that number.
It's a bit easier on the highway.
I'd prefer they say something like,
'if you want to get at least 2xMpG, keep it under 65MpH on the highway.'
2024 Yukon Denali XL6.2l with upgraded 22" wheel package. About 2500 miles at this point in time.
Above 65-70 MPH MPG starts to tank. Also depends A LOT of how flat the roads are. Just pul up the Fuel Ecomony display that shows Instant MPG and you will see what the throttle does to fuel consumption.
From trip yesterday. About 30 miles was in town driving for the complete trip.
Above 65-70 MPH MPG starts to tank. Also depends A LOT of how flat the roads are. Just pul up the Fuel Ecomony display that shows Instant MPG and you will see what the throttle does to fuel consumption.
From trip yesterday. About 30 miles was in town driving for the complete trip.
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Doesn't the Denali have the 6.2? I heard the 6.2 does better on the highway than the 5.3.
Yes, Denali has the 6.2l. Forgot to add that in, just included it in the post.
With the torque the 6.2l has along with the 10 speed transmission, it seems that the engine RPM's are pretty low at cruising and you do not need much throttle to keep speed up unless the road has more of an incline. Even with a slight incline if the transmisson drops from 10th to 9th gear, the engine does not wind up. This gets better fuel economy than my 2005 6.0l Denali XL. I used to dead criuse control in the 2005 when I hit and incline. The Torque Converter Clutch would disable and the trans would drop from 4th to 3rd gear and the engine RPM would double!!! Not this 2024 on the same route, I can leave the cruise on and the inclines are easily conquered without any drama.
Engine RPM was around 1500 RPM at 70 MPH in the picture I took. I think this is pretty typical, only driving the truck 2500 miles so far.
Not sure what the 5.2l RPM is at 70 on typical configurations, might be spinning a few more RPMs?
I have a picture from the trip at 80mph it was 1750 rpm
And it was pretty flat roads... It seems to be getting better almost at 1k miles now
blanchard7684
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It wouldn't surprise me if the 6.2 had a bit better mpg than the 5.3 on the highway. The larger displacement doesn't need as rich of A/F ratio to get enough power to climb small hills or overcome headwinds.
Marky Dissod
Full Access Member
This statement no longer applies, now that O2 sensors force a 14.7 AFR whenever the driver presses down on the go-pedal.
(When lifting off, it COULD go as lean as 15.0 in rare situations,
and if load is high enough, it'll go into Power Enrichment to cool the combustion chamber and keep NOx low.)
With a 10speed, I'd not be surprised if a 6.2L would get equal or better MpGs than a 5.3L, under 70MpH at least.
I forgot to add that this includes the Range AFM delete module in my vehicle. Not sure if this hurts fuel economy much, assume it does at least a small bit and with the Auto Stop/Start disabled, in town while sitting stopped in any traffic, stop lights or stop signs, the vehicle is Averaging EXACTLY 0 MPG!
Given the size and weight of the vehicle, while having a V8 I have no complaints for the MPG I have been seeing so far. If you want economy get the Diesel, but depending on the fuel prices in the area and the few Diesel related issues, you need to do your homework to decide if you really want a Diesel. I initial considered one until I started researching and really did not like the idea of the oil pump belt needing replacement around 100-125k miles, I think I saw at todays prices this could be a $3k job.
Given the size and weight of the vehicle, while having a V8 I have no complaints for the MPG I have been seeing so far. If you want economy get the Diesel, but depending on the fuel prices in the area and the few Diesel related issues, you need to do your homework to decide if you really want a Diesel. I initial considered one until I started researching and really did not like the idea of the oil pump belt needing replacement around 100-125k miles, I think I saw at todays prices this could be a $3k job.
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