Mercedes SLK World banner

1 - 15 of 15 Posts

·
Super Moderator
Joined
·
11,599 Posts
I see a pic of a gas guage on empty and ign is not on.
 

·
Administrator - Founding Member since 2006
Joined
·
93,672 Posts

·
Super Moderator
Joined
·
11,599 Posts
ahh..It was REALLY faint. I see it now :tu:
 

·
Super Moderator
Joined
·
24,931 Posts
According to my neighbour we get 11mpg.

Hate to tell him we get 30 plus.
Unless with Davie and/or Pete.

Still better than 11 though.
 

·
Registered
Joined
·
644 Posts
So far the best I have managed is about 24-25mpg (US gallons). Then again that was with my cruise control set at 80-85mph, which means engine revs were staying above 2000rpm (2200-2400 IIRC).

My problem with the cylinder deactivation for improved fuel economy in the R172 55 is that it only works when travelling on level terrain or downhill. As soon as I hit a bit of an incline, it immediately kicks back into V8 mode. And unfortunately in the Texas hill country, smooth/flat roads are few and far between, so long stretches of V4 mode are rare.

Mixed city/highway usage is returning 20-21mpg on my drive to work (about 15 miles each way), which seems good considering my 350 and 43 both only averaged about 21-22mpg each week in the same usage routine.

I dont see how you folks are getting 31-34mpg at 70mph unless its relatively smooth/flat highways with little to no incline, especially on an r171 without cylinder deactivation. I think I might get around 26mpg with the cruise control set at 70mph, but will need to test it since I rarely cruise below 75-80mph on Texas highways. No way I will ever see 30+. Maybe the limited slip differential in the performance package is to blame? I've heard those can negatively impact fuel economy.

As soon as my wife gets her Toyota 4runner, I'll either be using her old C300 as my daily driver or trading it out on something more my speed to use as a daily so I can keep the miles low on the SLK55. After that fuel economy shmuel economy. 😄
 

·
Registered
Joined
·
113 Posts
So far the best I have managed is about 24-25mpg (US gallons). Then again that was with my cruise control set at 80-85mph, which means engine revs were staying above 2000rpm (2200-2400 IIRC).

My problem with the cylinder deactivation for improved fuel economy in the R172 55 is that it only works when travelling on level terrain or downhill. As soon as I hit a bit of an incline, it immediately kicks back into V8 mode. And unfortunately in the Texas hill country, smooth/flat roads are few and far between, so long stretches of V4 mode are rare.

Mixed city/highway usage is returning 20-21mpg on my drive to work (about 15 miles each way), which seems good considering my 350 and 43 both only averaged about 21-22mpg each week in the same usage routine.

I dont see how you folks are getting 31-34mpg at 70mph unless its relatively smooth/flat highways with little to no incline, especially on an r171 without cylinder deactivation. I think I might get around 26mpg with the cruise control set at 70mph, but will need to test it since I rarely cruise below 75-80mph on Texas highways. No way I will ever see 30+. Maybe the limited slip differential in the performance package is to blame? I've heard those can negatively impact fuel economy.

As soon as my wife gets her Toyota 4runner, I'll either be using her old C300 as my daily driver or trading it out on something more my speed to use as a daily so I can keep the miles low on the SLK55. After that fuel economy shmuel economy. 😄



I'm with you. I manage 20-21 in town and 22-23 on the freeway. Of course the cruise is set around 90 on the freeway trips and my foot isn't light in town, so that's part of it.
 

·
Registered
Joined
·
1,684 Posts
According to my neighbour we get 11mpg.

Hate to tell him we get 30 plus.
Unless with Davie and/or Pete.

Still better than 11 though.
I don't think your neighbour is far off the mark. My o/b computer says over the last 10,000 miles or so, around 15 mpg, +/- a few tenths.

I can get 30mpg on a run, driving like a sissy - but that's not real world.
 

·
Registered
Joined
·
81 Posts
400 miles today, average of 27.1. Mainly motorway, some city, some country lanes.

Quite happy with that, especially sitting static on the M25 for hours on end just guzzling fuel with the aircon on.

As I'm doing it again next week, I'll stick it in comfort and try to squeeze max mpg. Until I see an empty road that is, and then I just can't resist it...
 

·
Premium Member
Joined
·
1,404 Posts
If I could keep out of the happy pedal, I would probably get 20 in mine.. got 16.5 on my last tank and that included an autocross event.

...and I have to do the calculations, no fancy computer telling me what mine is!
 

·
Registered
Joined
·
3,408 Posts
I actually got 33 miles to the gallon when I took the Garbage Scow home when I purchased it. I got on the highway right from the dealership, set cruise control to 55 miles an hour and drove it 90 miles. It is possible.
 

·
Registered
Joined
·
644 Posts
Are some of you talking imperial gallons? Those are bigger than US gallons arent they?

Interesting bit today, I shut off the cylinder deactivation and stayed in V8 mode the entire way to work and my car is showing 22.1mpg. Granted that was one 15mile 1way trip but still, daily "from start" mpg has been lower when letting it go into V4 mode. So confused.
 

·
Registered
Joined
·
24 Posts
I get 35+ (UK mpg) on my 80 mile round trip commute. Mainly on the A38 and M1 so sat at 70mph on cruise control (73mph according to the speedo, 70 mph according to satnav) but then mines only a 1.8 SLK200 not a chuncking big V8 job!!
 

·
Registered
Joined
·
246 Posts
I get 35+ (UK mpg) on my 80 mile round trip commute. Mainly on the A38 and M1 so sat at 70mph on cruise control (73mph according to the speedo, 70 mph according to satnav) but then mines only a 1.8 SLK200 not a chuncking big V8 job!!
Plus one!

Got 38 MPG (UK), doing a trip back from North Wales back to Sussex.
 
1 - 15 of 15 Posts
Top