5.3 vs 3.0 diesel

Madeindetroit92 · July 26, 2021

Hey guys so I made the decision to leave Mopar and hopefully join the GM family. I’m looking at the AT4/Trail Boss but I’m not sure which engine to go with! I’m debating between 5.3 or 3.0 duramax.
I won’t be hauling anything lol I’m just looking to get good MPG specifically comparing to my current SRT charger 2014 averaging 9.5 mpg (cammed) 180 miles per tank
I’m done with this garbage mpg and the rear wheel drive and service Department LOL
So the main question is which engine is best for mpg? I did some research and the diesel guys bashed out the gas guy and vise versa LOL

thank you in advance guys.

btj_z71 · July 26, 2021

54 minutes ago, Madeindetroit92 said:

Hey guys so I made the decision to leave Mopar and hopefully join the GM family. I’m looking at the AT4/Trail Boss but I’m not sure which engine to go with! I’m debating between 5.3 or 3.0 duramax.
I won’t be hauling anything lol I’m just looking to get good MPG specifically comparing to my current SRT charger 2014 averaging 9.5 mpg (cammed) 180 miles per tank
I’m done with this garbage mpg and the rear wheel drive and service Department LOL
So the main question is which engine is best for mpg? I did some research and the diesel guys bashed out the gas guy and vise versa LOL

thank you in advance guys.

Sounds like MPG is your main concern. In that case, the 3.0L Duramax is the clear winner.

My concern is your need for horsepower. I bet if you got behind the wheel of the 6.2L Silverado then you'd love it. Plenty of HP.

Your unlikely to win many street races with the 3.0L Duramax. It's the quickest of all the three halfton diesels, but only 277hp. The torque is amazing, and so is the MPG. It's quiet, powerful, efficient, and comes paired with the 10-speed transmission, so it's also a smart and smooth powertrain.

If you want to add performance to the 3.0L Duramax, there are a few cold air intakes available and Banks will soon release their Derringer diesel tuner for this engine too.

PBrown1 · July 26, 2021

I have about 16000 miles on my 3.0L Duramax. So far I love it. I average 22 mpg city and I've gotten 30 mpg hwy (driving 75 mph or less) on numerous occasions. BTW, these numbers are based on tank to tank fill-ups, not the rolling average displayed on the instrument panel. Yes... I'm a bit of a nerd. Bottom line, I think it's pretty darn quick, quiet and very smooth. Lots more torque than a 5.3L (which I borrowed and drove in the past).

Since the Duramax has a 100k powertrain warranty (a big plus), I will not do any modifications during the warranty period.

Edited July 26, 2021 by PBrown1

Amcguy1970 · July 26, 2021

If only there was a website or two that had gas mileage information...

https://www.fueleconomy.gov/feg/Find.do?action=sbs&id=43100&id=43101

If you aren't hauling anything and mpg is a concern why not look at something that isn't a truck? A nice CUV or sedan/wagon would be perfect for you it sounds like. That or a midsize truck can do even better mpg's like the 2.8 diesel Colorado if off roading is part of the reason you want a truck.

What is wrong with your tune to be getting 9 mpg in your challenger? Do you just trailer it back and forth to the track? Even H/C with additional fuel pumps you shouldn't be getting anywhere near that low, might want to get that looked at...

Tyler

Donstar · July 26, 2021

Welcome to this forum! My vote is for the diesel but research and test-drive the 2.7 before deciding.

KARNUT · July 26, 2021

Funny how a person can make unrealistic claims how quickly people say WTH. My stroke, blown, 373 geared truck did way better fuel mileage than that. People forget or don’t realize this is an enthusiast site. I personally wouldn’t buy a diesel unless I was pulling. Even that would depend on weigh. I like performance and would sacrifice a few miles per gallon for that. Even if I was fuel mileage minded to the extreme. The break even price versus the other options with engine choices. Would I keep the vehicle long enough for that to matter.

Madeindetroit92 · July 26, 2021

2 hours ago, btj_z71 said:

Sounds like MPG is your main concern. In that case, the 3.0L Duramax is the clear winner.

My concern is your need for horsepower. I bet if you got behind the wheel of the 6.2L Silverado then you'd love it. Plenty of HP.

Your unlikely to win many street races with the 3.0L Duramax. It's the quickest of all the three halfton diesels, but only 277hp. The torque is amazing, and so is the MPG. It's quiet, powerful, efficient, and comes paired with the 10-speed transmission, so it's also a smart and smooth powertrain.

If you want to add performance to the 3.0L Duramax, there are a few cold air intakes available and Banks will soon release their Derringer diesel tuner for this engine too.

the only reason my concern the mpg because sometimes I fill up twice a week LOL

I'm done with the 6L family lol, sounds like 3.0 It is. and for the performance wise I'm keeping it stock not touching anything lol

Madeindetroit92 · July 26, 2021

1 hour ago, PBrown1 said:

I have about 16000 miles on my 3.0L Duramax. So far I love it. I average 22 mpg city and I've gotten 30 mpg hwy (driving 75 mph or less) on numerous occasions. BTW, these numbers are based on tank to tank fill-ups, not the rolling average displayed on the instrument panel. Yes... I'm a bit of a nerd. Bottom line, I think it's pretty darn quick, quiet and very smooth. Lots more torque than a 5.3L (which I borrowed and drove in the past).

Since the Duramax has a 100k powertrain warranty (a big plus), I will not do any modifications during the warranty period.

22 MPG average and 100K powertrain warranty I'm sold on that. yea I was considering the 5.3 not anymore !

thank you for the response

Madeindetroit92 · July 26, 2021

29 minutes ago, Amcguy1970 said:

If only there was a website or two that had gas mileage information...

https://www.fueleconomy.gov/feg/Find.do?action=sbs&id=43100&id=43101

If you aren't hauling anything and mpg is a concern why not look at something that isn't a truck? A nice CUV or sedan/wagon would be perfect for you it sounds like. That or a midsize truck can do even better mpg's like the 2.8 diesel Colorado if off roading is part of the reason you want a truck.

What is wrong with your tune to be getting 9 mpg in your challenger? Do you just trailer it back and forth to the track? Even H/C with additional fuel pumps you shouldn't be getting anywhere near that low, might want to get that looked at...

Tyler

nothing wrong with the tune.

274 comp cam. long tube headers catless. zoomers exhaust, intake and HP tune. and a little heavy foot.

I looked into those and they don't look as good

Madeindetroit92 · July 26, 2021

27 minutes ago, Donstar said:

Welcome to this forum! My vote is for the diesel but research and test-drive the 2.7 before deciding.

thank you. where I live no one sell 2.7

mostly 3.0 diesel or 5.3

econometrics · July 26, 2021

I love my 5.3L in my 2019 RST... especially with the GM Performance Exhaust and Cold Air Intake. But my next truck will have a 3.0L diesel in it. You just cannot beat that MPG. And gas prices are going nowhere but UP in the days ahead.

f8l vnm · July 26, 2021

Something tells me we will have a updated 5.3 and 6.2 HP/TQ numbers on the 22 refresh.

Heck its been same output for 8 model years now. ( i just don't think the Oil burner will get a power bump)

mjonesjr84 · July 26, 2021

2 hours ago, Amcguy1970 said:

If you aren't hauling anything and mpg is a concern why not look at something that isn't a truck? A nice CUV or sedan/wagon would be perfect for you it sounds like. That or a midsize truck can do even better mpg's like the 2.8 diesel Colorado if off roading is part of the reason you want a truck.

My '20 RST crew cab short bed 4wd 3.0 Duramax gets better mpg than my '20 Equinox 2.0T AWD does by 20-30% (yes you read that correctly). On average, my Equinox gets 22 mpg with the wife driving it in front wheel drive mode. When I drive it, it averages 20 mpg. My 3.0 Duramax gets 26 mpg in the city and 29-30 mpg on the highway. Needless to say when we take family outings, the 3.0 is the vehicle of choice 90% of the time. These averages are hand calculated at each fill-up.

Now, you will say "diesel cost more per gallon and maintenance cost". However, diesel where I live is lower by about $0.30 per gallon than the 92 octane suggested in the 2.0T. Diesel is also only about $0.05 per gallon more than 87 octane the 5.3 would take. As far as maintenance cost go, the 3.0 oil change & tire rotation from the dealership I frequent is only $23 more than the 2.0T Equinox.

You can see in the attached Fuel Mileage Excel file what I have gotten for mpg since I've owned the truck. This is every fill-up. The worst is highlighted in RED and the best in GREEN. The worst mpg inputs were when I was pulling a box trailer moving my Grandpa. I will say that I do have a BAK Flip MX4 on the truck and I have the 18" wheels instead of the 20" (18" wheels have 31.5" tires and 20" wheels have 33" tires). I also have an AFe high flow air filter installed in the OEM airbox.

The 3.0 is not a speed demon. However, it will get you to speed in a hurry. It has the same torque rating as the 6.2. The 3.0 also comes with a 100k mile powertrain warranty. It has the 10-speed transmission where some of the 5.3 engines still have the 8-speed. The only complaint that I have on the 3.0 is pull out and passing power.

Fuel Milage.xlsx

Edited July 26, 2021 by mjonesjr84

KARNUT · July 26, 2021

13 minutes ago, mjonesjr84 said:

My '20 RST crew cab short bed 4wd 3.0 Duramax gets better mpg than my '20 Equinox 2.0T AWD does by 20-30% (yes you read that correctly). On average, my Equinox gets 22 mpg with the wife driving it in front wheel drive mode. When I drive it, it averages 20 mpg. My 3.0 Duramax gets 26 mpg in the city and 29-30 mpg on the highway. Needless to say when we take family outings, the 3.0 is the vehicle of choice 90% of the time. These averages are hand calculated at each fill-up.

Now, you will say "diesel cost more per gallon and maintenance cost". However, diesel where I live is lower by about $0.30 per gallon than the 92 octane suggested in the 2.0T. Diesel is also only about $0.05 per gallon more than 87 octane the 5.3 would take. As far as maintenance cost go, the 3.0 oil change & tire rotation from the dealership I frequent is only $23 more than the 2.0T Equinox.

You can see in the attached Fuel Mileage Excel file what I have gotten for mpg since I've owned the truck. This is every fill-up. The worst is highlighted in RED and the best in GREEN. The worst mpg inputs were when I was pulling a box trailer moving my Grandpa. I will say that I do have a BAK Flip MX4 on the truck and I have the 18" wheels instead of the 20" (18" wheels have 31.5" tires and 20" wheels have 33" tires). I also have an AFe high flow air filter installed in the OEM airbox.

The 3.0 is not a speed demon. However, it will get you to speed in a hurry. It has the same torque rating as the 6.2. The 3.0 also comes with a 100k mile powertrain warranty. It has the 10-speed transmission where some of the 5.3 engines still have the 8-speed. The only complaint that I have on the 3.0 is pull out and passing power.

Fuel Milage.xlsx 13.57 kB · 2 downloads

Bad comparison. Just doing a quick search. There’s about a 15K price difference. The difference in mileage not seeing that either. I can understand preferring the truck on trips for most people. I’m the opposite. Let’s be fair about the comparison.

mjonesjr84 · July 26, 2021

34 minutes ago, KARNUT said:

Bad comparison. Just doing a quick search. There’s about a 15K price difference. The difference in mileage not seeing that either. I can understand preferring the truck on trips for most people. I’m the opposite. Let’s be fair about the comparison.

I wouldn't say $15K since the Equinox is a Premier, but you can easily say $10K. You can or can't see the difference in mileage, but since I am the one who fills both vehicles up (wife hates to get gas), I know what both get for mpg.

Believe what you want on the 2-vehicle comparison (RST 3.0 vs Equinox 2.0T) of vehicles I own, but even the EPA's site shows the Equinox cost more to drive. You can see the personalized info as for driving I used on the bottom. I also used fuel cost in my hometown (regular - $3.09, Premium - $3.69, Diesel - $3.08). I'm getting more than TWICE the amount of miles per tank than the Equinox gets. I average right at 700 miles per tank in my 3.0. I don't wait that long to fill up though. Per the EPA info below, you will have to stop in 200 miles earlier in the 5.3 than the 3.0 and the cost to fill the tank will be the same.

After you look at the cost to buy each, the cost to drive each, and the resale/trade-in value. I'd still go with my 3.0 over either of the three. The 3.0 is only a $1k option over the 5.3 in the 2021 model year in a RST; in the LTZ it is only a $750 option.

Edited July 26, 2021 by mjonesjr84