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Garage => Test Drive => Topic started by: Motorman on 17 July 2021, 10:24 AM

Title: W116 Such Gas Hogs. Why ?
Post by: Motorman on 17 July 2021, 10:24 AM
Howdy
Still considering rescuing a 1973 450 SEL.
It's my understanding that these are quite thirsty when it comes to petrol.(12 mpg).
I would use it as a weekend putter so it wouldn't be drinking too bad.
At least as a low compression engine it should do well on non ethanol regular gas.
Anyone have some ideas on why they were such consumers ??
Thanks for your thoughts.
Title: Re: W116 Such Gas Hogs. Why ?
Post by: daantjie on 17 July 2021, 11:24 AM
12mpg is more 6.9 territory.   A well sorted 450 should be getting better than that.
Title: Re: W116 Such Gas Hogs. Why ?
Post by: ptashek on 17 July 2021, 11:51 AM
12mpg for a 450 is quite a lot.

I think 13 is the worst I ever got in regular use, and normally closer to 14.5 - 14.7. That's on a euro engine.

But yeah, they're hungry however you look at it.
Title: Re: W116 Such Gas Hogs. Why ?
Post by: rumb on 17 July 2021, 03:54 PM
That time period emissions control systems were crude and usually at the expense of performance.

You should be measuring smiles/miles instead.

Title: Re: W116 Such Gas Hogs. Why ?
Post by: 90077merc on 17 July 2021, 06:12 PM
Do the 450 SELs run better on low ethanol gas? Where do you find that?
Title: Re: W116 Such Gas Hogs. Why ?
Post by: Randys01 on 17 July 2021, 06:51 PM
 15-20 mpg should be quite achievable for a D jet....they are thirstier than the K Jet.

Not sure what spec this car is you are contemplating.Euro?/Cal?/US spec but when u say low compression I guess you mean 8:! which was normal US spec for M117.?
There will be plenty of debate from the US fraternity about their expeirinces with the best fuel and octane for this spec vehicle.


 

Title: Re: W116 Such Gas Hogs. Why ?
Post by: karmann_20v on 18 July 2021, 08:21 PM
Well... That gearbox with its many speeds may have something to do with it, me thinks. ALL 3 of them!
Title: Re: W116 Such Gas Hogs. Why ?
Post by: Motorman on 20 July 2021, 09:13 PM
Quote from: 90077merc on 17 July 2021, 06:12 PM
Do the 450 SELs run better on low ethanol gas? Where do you find that?

Hi
Our local farm service co-op has regular non-ethanol, which is handy since my SL runs fine on it. Off island you can actually get premium non-ethanol which is a great option for higher compression engines. Prices are high for both but since retired, no more commuting!!
Title: Re: W116 Such Gas Hogs. Why ?
Post by: BCDC on 20 July 2021, 09:35 PM
The fuel usage with the wonderful cars is never going to be great. It's a basic law of physics. These vehicles are HEAVY and this is the main reason for not brilliant fuel economy. Sure, it is best practice to get the thing running smoothly but you will never get outstanding economy even driving long distances at low RPM. Enjoy the car for what it is, a luxury saloon. When I first got mine I would work out the fuel usage when filling up but let that go a while ago, now I don't care and never think about it unless I read a post on this forum like this. I spend most of the time enjoying the experience of such a beautiful drive. I must admit that here in Australia we have access to 98 high octane fuel available almost everywhere, so I just fill her up with the best stuff and floor it. Enjoy the last gap of fossil fuels.

BC
Title: Re: W116 Such Gas Hogs. Why ?
Post by: revilla on 20 July 2021, 11:20 PM
Quote from: BCDC on 20 July 2021, 09:35 PM
The fuel usage with the wonderful cars is never going to be great. It's a basic law of physics. These vehicles are HEAVY and this is the main reason for not brilliant fuel economy. Sure, it is best practice to get the thing running smoothly but you will never get outstanding economy even driving long distances at low RPM. Enjoy the car for what it is, a luxury saloon. When I first got mine I would work out the fuel usage when filling up but let that go a while ago, now I don't care and never think about it unless I read a post on this forum like this. I spend most of the time enjoying the experience of such a beautiful drive. I must admit that here in Australia we have access to 98 high octane fuel available almost everywhere, so I just fill her up with the best stuff and floor it. Enjoy the last gap of fossil fuels.

BC


Never ever better stated. 10000% agree. It's like that other practice of keeping records of expenses on parts etc for the old girls. I hate when my accountant asks these type of questions. Wives/girlfriends have that bad habit too.  Calculating and knowing fuel consumption figures and total repair/maintenance expenses in my mind is inversely proportional to the pleasure level of owning classic cars. I personally prefer ignoring them.
Title: Re: W116 Such Gas Hogs. Why ?
Post by: ptashek on 21 July 2021, 07:31 AM
Quote from: revilla on 20 July 2021, 11:20 PM
I hate when my accountant asks these type of questions. Wives/girlfriends have that bad habit too.  Calculating and knowing fuel consumption figures and total repair/maintenance expenses in my mind is inversely proportional to the pleasure level of owning classic cars. I personally prefer ignoring them.

...and insurance companies, too.

I'm currently going through a soap drama level back and forth with my insurance company to get my agreed value insurance renewed. All these records suddenly became very helpful.
Title: Re: W116 Such Gas Hogs. Why ?
Post by: JeffCullen on 27 July 2021, 09:23 PM
Nice thing is they shoved a tractor engine in for a couple of years ;)

I drive a good mix of city and highway... and I don't drive slowly. 24MPG average.

Sure, I'm not beating anyone who's trying through an intersection, but that's not what any W116 is about.  I don't find myself needing to go over 105MPH too often either.

Yes, the petrol cars are quieter and more refined... but a OM617 running properly really does demonstrate why folks spent so much money on these cars back in the day -- and the soothing agricultural whir exhibits a certain je ne sais quoi. The difference between a tired engine with collapsed mounts vs a minter with everything fresh is astonishing.

Sorting any of these cars out to the point where everything feels and works as new isn't cheap, but once you're there, the operating costs of the 300SD are COMICALLY inexpensive. There are so many rough examples out there, but if you can find a good one, it's a phenomenal classic car hack.