Fuel Economy - C350
Newbie
Joined: Mar 2005
Posts: 3
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2008 C350 4matic
I average 29-30mpg on the highway at 60-65mph.
On the non premium fuel issue - modern ecus will adjust timing and mixture to prevent knock due to differences in fuel characteristics, so using regular instead of premium won't damage your engine - but you won't get 268 hp or the published mileage figures either. It'll make less power and increase fuel consumption, so you won't be any further ahead.
I average 29-30mpg on the highway at 60-65mph.
On the non premium fuel issue - modern ecus will adjust timing and mixture to prevent knock due to differences in fuel characteristics, so using regular instead of premium won't damage your engine - but you won't get 268 hp or the published mileage figures either. It'll make less power and increase fuel consumption, so you won't be any further ahead.
MBWorld Fanatic!
Joined: Mar 2007
Posts: 2,408
Likes: 3
Running a lower than required octane can cause engine damage from preignition and carbon buildup. Plus, the losses to fuel economy will cost more than the premium fuel. If you can not afford the fuel, you should not be driving the car.
MBWorld Fanatic!
Joined: Feb 2004
Posts: 3,986
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From: SEATTLE WASHINGTON USA
'08 C300 Lux Barolo Red Beige Leather P2 MM 18" wheels '84 944
Nope
<<<6. Let off the gas and coast or put in neutral when heading towards red lights or stale green lights. Why have your foot on the pedal or the cruise on when you are going to be stopping anyway. >>
If you think this saves gas, you should learn something about modern fuel injection.
When you lift off the gas pedal when slowing, fuel flow stops, resuming when idle speed is reached. Even my 25 year old Porsche's Motronic system does this.
Therefore, you are using more fuel, not less, by coasting in neutral because the engine will be idling and using fuel. This is also illegal in most jurisdictions because it's unsafe.
If you think this saves gas, you should learn something about modern fuel injection.
When you lift off the gas pedal when slowing, fuel flow stops, resuming when idle speed is reached. Even my 25 year old Porsche's Motronic system does this.
Therefore, you are using more fuel, not less, by coasting in neutral because the engine will be idling and using fuel. This is also illegal in most jurisdictions because it's unsafe.
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Joined: Jan 2008
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C300 Sport/Palladium Silver on Black/P2
Why not have the car perform and run as intended? $100 bucks a year if you use a tank a week like me or something, not worth it.
MBWorld Fanatic!
Joined: Jun 2008
Posts: 1,309
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2016 C63S
Isn't the octane higher in Europe? I know in Holland regular is 95 and super is 98.
It will make the car run a little warmer and help with fuel consumption.
My friend in Holland told me he just paid $1.67 for 1 LITER of regular. That's like paying almost $10 for a Gallon!!
It will make the car run a little warmer and help with fuel consumption.
My friend in Holland told me he just paid $1.67 for 1 LITER of regular. That's like paying almost $10 for a Gallon!!
Senior Member
Joined: Feb 2008
Posts: 300
Likes: 2
From: Toronto
2008 c300
Isn't the octane higher in Europe? I know in Holland regular is 95 and super is 98.
It will make the car run a little warmer and help with fuel consumption.
My friend in Holland told me he just paid $1.67 for 1 LITER of regular. That's like paying almost $10 for a Gallon!!
It will make the car run a little warmer and help with fuel consumption.
My friend in Holland told me he just paid $1.67 for 1 LITER of regular. That's like paying almost $10 for a Gallon!!
Thread Starter
Junior Member
Joined: Sep 2007
Posts: 16
Likes: 0
From: Maryland
2008 C350 Black with Black MB Tex
Here are the current readings since the reset. I have to say that I drive my car much more normally than when I started this test. Now I just drive it to have fun and really pay no attention to the MPGs. So 24.1 MPG avg is pretty darn good for a car that has 17/25 on the sticker with a 20 combined MPG avg.:
4123 mi
24.1 MPG
111:04 h
37 mph avg.
total mileage on car: 27,808
Last edited by TomGator1; Apr 29, 2010 at 09:41 AM.
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Senior Member
Joined: Mar 2008
Posts: 418
Likes: 1
08 MB
i went out today to check my tires and the original tire valve stems that came with my C350 were gone. There are now cheap gray plastic ones on there. I'm positive someone at the dealership did it. A regular thief would not have replaced the stems! If any of you would do me a favor and post a few pics of your original C350 tire valve stems, I would appreciate it!
Senior Member
Joined: Mar 2008
Posts: 418
Likes: 1
08 MB
As far as feeling the differences in power that will all depend on the conditions and how much timing is pulled. If all you do is light acceleration and cruising then lower octane is fine as there will be no difference.
Thread Starter
Junior Member
Joined: Sep 2007
Posts: 16
Likes: 0
From: Maryland
2008 C350 Black with Black MB Tex
They were sort of silver colored plastic, and longer than normal. They were much better quality than the cheap gray plastic ones that are on there now.
