2021 Sierra 1500 Crew Cab 6.2L w/10spd trans fuel economy

Grumpy Bear · June 16, 2021

16 minutes ago, Amcguy1970 said:

Should let the engineers, designers and testers know you found something they missed in the hundreds of thousands of hours of design and millions of miles of testing...

So no facts, no back up or experience just an assumption of yeah you have a feeling this is going to horribly damage a key internal part of the engine you have no experience with and instead choose to spread fears to others

Tyler

I don't know about pushrod bending but...you've never replaced a worn out starter pinion/bendix or flywheel ring gear? A fraction of the cycles of stop start. You've never notice the fuel DUMP of a GDI motor on each start up? Without it UOA will show over 2% fuel dilution and they call it normal. Just saying.

They have an agenda and you ain't on it!

June 16, 2021

1 hour ago, kodiakdenali said:

Don't have the exact numbers but I'm getting low-mid 20's (mostly low) I can easily get over 20 on the highway which is a very nice update from my last truck which gave me 12-14 even on the interstate. 2020 Sierra Denali crew cab, standard bed, 6.2L 10 speed, Whipple supercharged. auto stop-start disabled and after doing my exhaust video (on my youtube channel) and really paying attention to the sound and the throttle response, I pretty much drive in L mode at all times now = no DFM, and I only shift it up to L10 to allow DFM to operate when I'm cruising on the interstate.

full size pickup, huge engine, largest body configuration, a handful short of 600bhp, and 22-24mpg on the highway....life is good in my garage.

Wow, you are getting that with the supercharger? That might push me over the edge in getting it. I would like a little more power.

kodiakdenali · June 16, 2021

2 minutes ago, 1454 said:

Wow, you are getting that with the supercharger? That might push me over the edge in getting it. I would like a little more power.

Pretty amazing tech! it has a bypass valve on it which allows air to completely bypass the compressor and go straight into the engine. When you're not asking the engine for a lot of power, the supercharger basically does nothing, just spins freely with no air in it. Whipple claims around 1hp parasitic power loss. then when you do want the power the bypass closes, the compressor gets air and all sorts of amazing stuff happens.

Pineapple30 · June 25, 2021

On 6/10/2021 at 11:35 AM, AwwWhatThe said:

What are you all experiencing for MPG/fuel range in your rides? Brand new here (30 miles) and Im getting 5 mpg and a range of 220 max. Im sure it will get better but just looking at whats out there.

Im coming from a 2015 Sierra 1500 w/ 5.3L 8spd trans and I would get roughly 14 mpg city and 20-23 highway with a range of over 450

Has that improved much for you?

I'm not getting as low MPG as you, one month into ownership, but at 11 mpg, I'm getting significantly less than what I'm seeing most people post. I drive slow like a granny, so it seems wrong.

GullLakeMi · June 26, 2021

On 6/15/2021 at 10:07 AM, Grumpy Bear said:

Yes! A 4.3 and a six speed!

Kidding aside; books are written on this topic and I think I could add a few paragraphs to most of them. Trip length...

It's hard to imagine how much impact trip length has on fuel economy. If you could find a really flat piece of road after the truck is fully warmed up, driving over an hour interstate highway, on a windless day and drive that around 48-53 mph observing your 'instant' meter you will know approximately what your truck is capable of. Now...how much of that you get to keep is up to your choices and your circumstances. We can't control everything.

In that first hour of driving most of what you don't get to keep is used to bring fluids to heat reducing viscous drag. The colder the day the longer this takes. You start the day at zero mpg and for an hour it improves until it becomes the best it can be. That period of time will have an average. That average is a fraction of your trucks capability. That number you tested for earlier. Drive long enough and that average will get really close to your best. This could take a hundred miles or more.

Once up to heat that period of time used in building it's 'average' gets shorter and shorter. You've seen this on trips requiring more than one tank of fuel. Second tank is almost always better than the first and the third marginally better than the second.

Hint: NHRA Pro Stock class racers use 0W or 5W racing oil. Their trip length is a quarter of a mile and the oil temperature at the end of the quarter might not reach 100F. 5 weight oil it more viscous at 104 F than 60W is at 212 F.

Next two biggest users of fuel are a Micky D's drive through and taking the wife anywhere.

I couldn't imagine reading a book on this topic, but do appreciate the cliff notes.

In Michigan, 55mph is the minimum legal speed and a great way to get run over. Agree that might be the optimal speed for gas mileage, but not practical in any way.

I've only had my '21 Sierra AT4 6.2L 10 speed for 2k miles. I was recently on a trip with a multiple car convoy. Leader was averaging 68 mph on interstate highway towing a trailer setting the slow pace. At that speed on relatively flat terrain, I averaged 25 mpg on best 25 mile segment and 24 mpg on best 50 mile segment. That was encouraging, but I usually set cruise at 8 over (78 mph) and seem to get about 21 mpg at that speed.

Grumpy Bear · June 26, 2021

7 minutes ago, GullLakeMi said:

I couldn't imagine reading a book on this topic, but do appreciate the cliff notes.

In Michigan, 55mph is the minimum legal speed and a great way to get run over. Agree that might be the optimal speed for gas mileage, but not practical in any way.

I've only had my '21 Sierra AT4 6.2L 10 speed for 2k miles. I was recently on a trip with a multiple car convoy. Leader was averaging 68 mph on interstate highway towing a trailer setting the slow pace. At that speed on relatively flat terrain, I averaged 25 mpg on best 25 mile segment and 24 mpg on best 50 mile segment. That was encouraging, but I usually set cruise at 8 over (78 mph) and seem to get about 21 mpg at that speed.

Michigan is one of two states with a minimum speed limit over 45 mph. Oklahoma the other 55-60 there depending on maximum. Only 10 states actually have a minimum Interstate speed limit. Some as low as 40 on the mainland. Hawaii 35.

I find it amusing at best people worry more about some guy doing the minimum than the majority doing 10-15 mph over. :wtf:

In this state a cop won't open his ticket book for less than 10 over so....people take it. Except school and construction zones. Pretty though on those. That's a good thing.

Funnier is the Semi that crawled up your bumper a mile ago flashing lights and honking horns can't hold the minimum pulling the next 5% grade. Honk at him

But if that is the minimum then driving it will yield gains, yes.

WeGone · June 28, 2021

Just over 1500 miles Avg 18-20. Best 24 on a trip. 13-14 towing a car trailer with a 3200lb car.

Z71-K9 · June 29, 2021

27,000 miles on my 2019. 15.5mpg in the city. Average 22mpg highway. Best 23.5mpg

Grumpy Bear · June 30, 2021

https://auto.howstuffworks.com/fuel-efficiency/fuel-economy/question477.htm

Edited June 30, 2021 by Grumpy Bear

JRB9921523 · July 1, 2024

I just traded my 2019 GMC 1500 Denali at 95k miles for a 2021 model equipped similarily with 32k miles. (I lost some cameras, but gained the adaptive cruise control option.) My 2019 overall got 19 mph regularly, and 23 on interstate trips (daily). And THE BEST for 25 miles was 32mpg; 28 mpg for the 50 mile interval and 23 mpg on the 400 mile trip interval. I was very pleased and therefore upgraded to the same just 2 years newer and the lower mileage bc during construction season I'm traveling 150 to 200 miles per day.

On my test drive, I noted that the 2021 showed much lower mpg for those same intervals. And the Trip 2 odometer memory was for the life of the vehicle (32,777 miles) and was only 15.5 mpg. I still purchased the 2021 under the assumption that the previous owner drove local in stop/go traffic with very little interstate mileage. The salesman who took it on trade for a new 2024 indicated it was an older gent who averaged less than 10k miles per year, bolstering assumption. My point here, is to show my 2019 experience for others to see. And, that once I season this 2021 to my driving habits I'm expecting that the 2021 mpg will improve closer to my previous experience given its the same 6.2L and 10 speed tranny for the same crew cab short bed truck.