W126 500SE Versus 300SE

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Roygarth

Active Member
Joined
Aug 12, 2009
Messages
99
Location
Norfolk
Car
1983 W123 230E
I had a W126 500SE for 2 years a few years ago - loved it. Thinking its time for another W126.

Wondering if this time I should try 300SE for economy reasons.

What is the real out of town A/B road MPG of the 300SE compared with the 500SE?

I'm worried the 300SE will feel underpowered. How does the performance compare with the 500SE?

Thanks!
 
Petrol wise I suspect it'll much of a muchness, smaller engine pushing similar weight and all that.
 
I get aprox 20mpg around town, 25mpg out of town mixed roads and 30mpg motoway at 65-70mph.

Having never driven a 500 I can't compare but I find the M103 3.0l in my S to be more than adequate. Very torquey and can certainly pick up it's skirt tails and run when prodded.
 
Between 2 & 5mpg more out of the 300. Up to you wether it's worth it.
 
Never seen 30 anywhere, 18 at best on a tank full of around town, 26 possible on motorways at steady 80 on speedo... 50k miles over last 30 months.
Whatever you go for a truly fabulous experience, nil depreciation and as I've said before, you always arrive in style.
 
Hello Roygarth, I remember you asking for advice on here re that 500SE. I'm glad it turned-out well for you.

You might want to give fuelly.com a browse.

It states the 300SE as returning 23.5 mpg over more than 10k miles.
There's a 420SEL out of which one guy manages to eke 23.3mpg. There aren't any 500's but the 560's get 18mpg. I think any way you look at it, these cars have drinking issues.
 
You might want to give fuelly.com a browse.

Ah, I've often wondered what these fuelly tag thingamabobs were on some signatures. Now I know and in the spirit of learning and adventure I thought I'd look see what my two thirstiest beasts (the MBs ) drink. In fact I am none the wiser as neither are listed.:eek::D
 
From what I recall there's little or no difference in mpg between the two, I think the 300 only scored a bit better on just the city cycle and was the same as the 500 @ 56 & 75mph.
I do have the figures somewhere if I come across them I'll post up.
 
The 300's have a higher (oh god, is it lower?) final ratio and that kills the economy.

As John J jr says, there's not a lot in it.

I got 27mpg on a run, 24ish overall during my 3 year fling with a 300SE.

I would have liked a bit more power, and at motorway speeds iirc I was at around 3k revs and you noticed there was an engine at work. My dad's 500SEC hovered around 2k rpm on the motorway. That and a lot more torque is what differentiates the two. Oh, and kickdown from 70:)
 
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Ah, I've often wondered what these fuelly tag thingamabobs were on some signatures. Now I know and in the spirit of learning and adventure I thought I'd look see what my two thirstiest beasts (the MBs ) drink. In fact I am none the wiser as neither are listed.:eek::D

More reason to sign up and share your pain with the rest of us:D
 
Thanks Guys....can't believe I was flirting with the idea of a 6 cylinder W126. If all goes to plan I'll have a 500SEC on Monday :D
 
Hi,

I bought a 300SEL equipped with LPG earlier this year, it returns 19mpg on gas. I prefer the engine to the 24v version I had in a coupe, it seems to be happier sooner.

I‘ve had a 420 a 500 and a few 560’s and always thought the M103 would be inadequate without giving it a try. Now I’ve tried it, and I don’t think it’s underpowered at all, it’s just not as powerful as the others!

It’s extremely respectable and I haven’t once craved those other horses.

My wife rarely drives any of my cars, but when she does she occasionally likes to slap them about a bit. We (four) were coming back from a Belgian Beer sampling afternoon and as the sober one she did her bit; on a very straight piece of road she floored the thing and we all watched the speedo move toward one hundred mph, getting ready to applaud as the three figures arrived - just as it hit the hundred it moved into top. Loud cheer.

I think she’d left it on the petrol.

Cheers,

Paul
 
Thanks Guys....can't believe I was flirting with the idea of a 6 cylinder W126. If all goes to plan I'll have a 500SEC on Monday :D


I think you were wise to consider the 6-banger and should still do so.

No W126 will ever return good fuel economy although I suspect that in the real world the 300SE will be noticeably less thirsty than the larger-engined models.

But it isn't all about fuel economy. The M103 engine is a relatively straightforward unit and is pretty accessible for DIY maintenance and other jobs. The 420 and 500 V8s are less likely to fall within the scope of a home-mechanic due to increased complexity and reduced access.

The fact that you are concerned about fuel economy suggests that you have a limited budget so I would go for the 300SE every time. If driven sensibly a good one is a comfortable and effortless cruiser.
 
I think you were wise to consider the 6-banger and should still do so.

No W126 will ever return good fuel economy although I suspect that in the real world the 300SE will be noticeably less thirsty than the larger-engined models.

But it isn't all about fuel economy. The M103 engine is a relatively straightforward unit and is pretty accessible for DIY maintenance and other jobs. The 420 and 500 V8s are less likely to fall within the scope of a home-mechanic due to increased complexity and reduced access.

The fact that you are concerned about fuel economy suggests that you have a limited budget so I would go for the 300SE every time. If driven sensibly a good one is a comfortable and effortless cruiser.

Have just sold my '97 Bentley Turbo R daily driver, so both 6 and 8 cylinder W126 will be a big improvement on the fuel economy front! And as my DIY does not extend much beyond checking the oil, accessibility is not a big concern.

My original question was, I suppose, me wondering if there was a big difference in fuel economy between the 6 and 8 cylinder engines to compensate for the big bhp/torque difference.

Eventually I decided to go with an SEC so 6 cylinder not an option anyway.

Best, Piers.
 
Have just sold my '97 Bentley Turbo R daily driver, so both 6 and 8 cylinder W126 will be a big improvement on the fuel economy front! And as my DIY does not extend much beyond checking the oil, accessibility is not a big concern.

My original question was, I suppose, me wondering if there was a big difference in fuel economy between the 6 and 8 cylinder engines to compensate for the big bhp/torque difference.

Eventually I decided to go with an SEC so 6 cylinder not an option anyway.

Best, Piers.

I used to have an early Mulsanne Turbo and a Turbo RL, On long journeys you had to plan the fuel stops quite carefully (or lift off the throttle a fair bit)

I consider the W126 V8 an economical car. I don't know what the mpg is but a tank lasts a good 300 odd miles on a run, not far off the 230te!
 
I consider the W126 V8 an economical car. I don't know what the mpg is but a tank lasts a good 300 odd miles on a run, not far off the 230te!

The 230TE is not really a good example of fuel-economy.
I ran a 380SE for some years.
Lovely car ... You don't buy them for fuel-economy ... But they are respectable in this respect.
I then ran a 230TE ... Fuel consumption was little different from the 380SE.
Pretty-disappointing, really.
 

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