Fuel usage

[Speedy Emira]

Just thought I’d see what fuel usage other owners are getting.
I just drove 150 miles each way to relatives and decided to test the difference between driving it as I like on the way and as fuel efficient as possible on the way back.
On both runs I used the air con and had the sound system on. In the I got 30.2 mpg and on the way back a pretty impressive 39.6mpg. I never thought in a million years thought it would be that low so took the picture:

 

[scc.131.fe]

Good topic! And I'm only speaking from past vehicle experience, but each Emira probably has a correction factor in the programming to equate injector-on times with gallons used, and then compares that with distance covered according to speed sensors. So not only would I suspect that the number is off a bit if your speedo says 58 when you actually doing 55, but also that the injector math may be off a bit.

My unprofessional opinion is that the best way to test is top off the tank, do the run down to relatives, check trip distance on the car with expected distance via google maps to see how many miles more or less the car THINKS it did, and then see how much gas you put back in to top off again. Repeat for the next leg.

 

[scc.131.fe]

Oh, and, it would be great if someone could confirm whether North American cars have their math setup for US gallons (3.8liters), not UK gallons.

 

[KAR120C]

Oh, and, it would be great if someone could confirm whether North American cars have their math setup for US gallons (3.8liters), not UK gallons.

You can set the units to either system.

 

[Speedy Emira]

Good topic! And I'm only speaking from past vehicle experience, but each Emira probably has a correction factor in the programming to equate injector-on times with gallons used, and then compares that with distance covered according to speed sensors. So not only would I suspect that the number is off a bit if your speedo says 58 when you actually doing 55, but also that the injector math may be off a bit.

My unprofessional opinion is that the best way to test is top off the tank, do the run down to relatives, check trip distance on the car with expected distance via google maps to see how many miles more or less the car THINKS it did, and then see how much gas you put back in to top off again. Repeat for the next leg.

I totally get it and I have never had a car that does the stated mpg or is 100% accurate, including cars like Mercs, Audis and BMWs. if it is only doing 55 and it thinks it is doing 58 that is 5% out. Even if you took off 5% and another 4% for other inaccuracies it would still be an impressive 36mpg.

I looked at CarWow to see what they said about the 2024 AMG A45S:

If good fuel economy is high up your shopping list, the A45 S might not be the A-Class for you. Official figures suggest you can get up to 34mpg, but we saw 26mpg with a mix of town, motorway and something we’ll simply refer to as 'enthusiastic driving'.

I could be wrong but on paper it looks like there isn't a massive difference between the V6 and the i4 if driven well, although the i4 will have better emissions I am sure. For the record I'm not fussed about the mpg because at 3000 miles a year it won't matter so did this for a bit of a laugh to see how bad it was, or this case prove me wrong.

 

[gdotp]

Yep that’s about what I got taking the car to the dealer 60 miles away for its wrap. Steady 70 to 75 seems to get high 30s….since it’s been run in Im getting a lot less …

 

[Speedy Emira]

Yep that’s about what I got taking the car to the dealer 60 miles away for its wrap. Steady 70 to 75 seems to get high 30s….since it’s been run in Im getting a lot less …

Because you are enjoying it more.

 

[lynchy73]

The I4 is efficient when driven sensibly on a run, but is not in the least bit efficient when you use the power. I typically see less than 20mpg (UK gallon) with spirited local drives.

 

[Eagle7]

If you're in the U.S., make sure you go into the car's settings and choose English U.S.

 

[Biggles of Norwich]

Just thought I’d see what fuel usage other owners are getting.
I just drove 150 miles each way to relatives and decided to test the difference between driving it as I like on the way and as fuel efficient as possible on the way back.
On both runs I used the air con and had the sound system on. In the I got 30.2 mpg and on the way back a pretty impressive 39.6mpg. I never thought in a million years thought it would be that low so took the picture:
View attachment 42889

V6 manual. Longest run so far, about 270 miles of mainly A road, some dual some single carriageway, and some B roads to avoid congestion on A roads. Car was showing 33.8 mpg, which is the best I've seen. However, I brimmed the tank at the end of the run, and using the cars mileometer it worked out at 35.93 mpg, all in UK gallons. It was a one way trip, so wind direction and speed may well have been a factor, either plus or minus.
However - that's just out of curiosity, I didn't buy it for its fuel economy, rather despite it's fuel economy!

 

[08fordgt]

2.0T engines are good for being efficient when cruising but also draining when excelerating. My Alfa Giulia which has an upgraded turbo and everything else with 400awd+HP gets 38mpg on the highway. It's funny but i find myself enjoying cruising more than I would in my Shelby.