Fuel economy 2015 e400 coupe 4matic?
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Joined: Oct 2011
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BMW 528i
Fuel economy 2015 e400 coupe 4matic?
Sooo, I'm now in the club with a V-6 Bi-turbo. Silly me, I thought the MPG would be better than my 2001 CLK55 AMG with the V-8, but I'm starting to doubt that and question the "efficiency" rationale for the upgrade!
With the M113 V-8, city MPG was bad - usually 10mpg-ish, but we know that. Highway ran about 24-25/mpg, acceptable for 360hp, and amazing for a 2001 era vehicle.
With the M276TT V-6 in the e400, going by the trip MPG tool, it's not even reporting as high as 10mpg in Eco mode puttering out of the parking garage and around the block. On highway drives, I don't see it reaching into 30mpg often, but it's a little more in the realm of what I thought I might see in high 20's.
Note: my gallon references at US Gallons.
Outside of highway travel, what sort of MPG are other e400 V-6TT drivers seeing *in-city* or at idle?
I'm going to run the old OBD instantaneous MPG gauges later this week to see how much the trip indicated MPG varies from the OBD readout.
With the M113 V-8, city MPG was bad - usually 10mpg-ish, but we know that. Highway ran about 24-25/mpg, acceptable for 360hp, and amazing for a 2001 era vehicle.
With the M276TT V-6 in the e400, going by the trip MPG tool, it's not even reporting as high as 10mpg in Eco mode puttering out of the parking garage and around the block. On highway drives, I don't see it reaching into 30mpg often, but it's a little more in the realm of what I thought I might see in high 20's.
Note: my gallon references at US Gallons.
Outside of highway travel, what sort of MPG are other e400 V-6TT drivers seeing *in-city* or at idle?
I'm going to run the old OBD instantaneous MPG gauges later this week to see how much the trip indicated MPG varies from the OBD readout.
Senior Member
Joined: Jul 2008
Posts: 296
Likes: 65
2015 E400
The cars brain is a bit wonky in terms of mileage and range. It will also depend on the type of driving you do. The best thing to do is to calculate the mileage yourself to see what the real mileage is. Top off the tank, reset the trip computer to 0 and top-off again after getting to 1/4 tank or lower, then note the gallons and total miles. Then compare that against the car's brain. You may be surprised.
As for my 2015 E400 Cab, if the top is up the entire trip and I do only relatively flat highway miles, it's not hard to get over 32mph. Conversely, if the majority of my driving is just short trips, less than 5 miles each, the mileage will drop to as low as 16.
Typically, i do probably 20% highway(avg spd 65mph), 30% surface road trips over 5 miles (avg spd 35-45mph), and 50% short trips less than 5 miles. This gets me about 18-20 mpg.
If I drive top-down, it's a different story, but not that much worse.
As for my 2015 E400 Cab, if the top is up the entire trip and I do only relatively flat highway miles, it's not hard to get over 32mph. Conversely, if the majority of my driving is just short trips, less than 5 miles each, the mileage will drop to as low as 16.
Typically, i do probably 20% highway(avg spd 65mph), 30% surface road trips over 5 miles (avg spd 35-45mph), and 50% short trips less than 5 miles. This gets me about 18-20 mpg.
If I drive top-down, it's a different story, but not that much worse.
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Joined: Mar 2022
Posts: 267
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From: Chicago
Bi-Turbo E550 Coupe (W207)
Something seems to be wrong with the trip computer calculations or there is something not working right with the engine. I'm consistenty averaging 23 mpg or higher with mix of highway (60%) and city (40%). I have checked the mileage as well as the trip computer and they are spot on. I am driving the V-8 turbo M278 engine and its going better than I anticipated for fuel economy. I typically average on long highway drivers over 28 mpg and even hit over 30 mpg for some of the stretches.
I will say at idle or just doing a lot of city driving will have much lower mpg, around 14-18 mpg for me. Idling will always use more fuel than necessary, there's no engine cut off on my year model either so it will run down the mpg to be stuck at stop lights.
I will say at idle or just doing a lot of city driving will have much lower mpg, around 14-18 mpg for me. Idling will always use more fuel than necessary, there's no engine cut off on my year model either so it will run down the mpg to be stuck at stop lights.
Last edited by ibbij; Sep 26, 2024 at 08:53 AM.
Junior Member
Joined: Feb 2020
Posts: 19
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(2008 Audi a4 Quatto 2.0t S-line)(2016 E400 Coupe)
Decent
Sooo, I'm now in the club with a V-6 Bi-turbo. Silly me, I thought the MPG would be better than my 2001 CLK55 AMG with the V-8, but I'm starting to doubt that and question the "efficiency" rationale for the upgrade!
With the M113 V-8, city MPG was bad - usually 10mpg-ish, but we know that. Highway ran about 24-25/mpg, acceptable for 360hp, and amazing for a 2001 era vehicle.
With the M276TT V-6 in the e400, going by the trip MPG tool, it's not even reporting as high as 10mpg in Eco mode puttering out of the parking garage and around the block. On highway drives, I don't see it reaching into 30mpg often, but it's a little more in the realm of what I thought I might see in high 20's.
Note: my gallon references at US Gallons.
Outside of highway travel, what sort of MPG are other e400 V-6TT drivers seeing *in-city* or at idle?
I'm going to run the old OBD instantaneous MPG gauges later this week to see how much the trip indicated MPG varies from the OBD readout.
With the M113 V-8, city MPG was bad - usually 10mpg-ish, but we know that. Highway ran about 24-25/mpg, acceptable for 360hp, and amazing for a 2001 era vehicle.
With the M276TT V-6 in the e400, going by the trip MPG tool, it's not even reporting as high as 10mpg in Eco mode puttering out of the parking garage and around the block. On highway drives, I don't see it reaching into 30mpg often, but it's a little more in the realm of what I thought I might see in high 20's.
Note: my gallon references at US Gallons.
Outside of highway travel, what sort of MPG are other e400 V-6TT drivers seeing *in-city* or at idle?
I'm going to run the old OBD instantaneous MPG gauges later this week to see how much the trip indicated MPG varies from the OBD readout.
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Joined: Oct 2011
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BMW 528i
Just completed a road trip from LA to Sacramento to get a feel for the car and performance + consumption.
Even though dark and rainy for 1/2 the trip, the e400 performed flawlessly - super easy drive, great passing power and 4matic instilled confidence maneuvering.
Over the 821 mile trip along I-5, with 13h 15m drive time, I got a round-trip 32.2 mpg (calculated from the gas receipts, tank level), which is in line with what my dash computer showed.
If I remove the 36 miles of Sacramento city driving, total highway MPG was around 33.5 mpg.
I'll get back to LA testing next week.
Even though dark and rainy for 1/2 the trip, the e400 performed flawlessly - super easy drive, great passing power and 4matic instilled confidence maneuvering.
Over the 821 mile trip along I-5, with 13h 15m drive time, I got a round-trip 32.2 mpg (calculated from the gas receipts, tank level), which is in line with what my dash computer showed.
If I remove the 36 miles of Sacramento city driving, total highway MPG was around 33.5 mpg.
I'll get back to LA testing next week.
