c350 cdi vs c350 cgi real world mpg????

[wilsodg]

This is a great thread I keep coming back to

I have a 2011 C350CDI and while I love the torque and sheer speed of the thing I will be going back to a petrol when I change it next year. Like Gizze I cannot put it down into words, just having a petrol with a better sound track is more appealing than gaining 5MPG and a rattle.

Whilstt I'm inclined to agree, I have more than a nagging concern that I'll miss the torque

 

[Magoo]

Only you can decide that

That's why this debate is so much fun! There is no RIGHT answer for everyone - your new car will be dependant on the order of preference that you personally give to price, performance, noise and torque bands, amongst other things.

It's either that or a V6 petrol !

 

[gIzzE]

I have done 98 miles today sat at 70mph and the E350cdi estate returned 45mpg, my best run by far.

This car is set up for 70 gearing wise, would much prefer it to be 80 though.

 

[Deleted member 37751]

I have done 98 miles today sat at 70mph and the E350cdi estate returned 45mpg, my best run by far.

This car is set up for 70 gearing wise, would much prefer it to be 80 though.

Is yours the 7G plus? That W212 350 CDi I had would piss 50mpg at 70mph.

Thinking on, have we had this conversation before, because I've got a sense of deja vu.

 

[Peter DLM]

I have done 98 miles today sat at 70mph and the E350cdi estate returned 45mpg, my best run by far.

This car is set up for 70 gearing wise, would much prefer it to be 80 though.

What revs was it pulling at 70mph?

 

[Peter DLM]

If was more than 1600rpm then you either lack the 7G+ or have it in Sport mode and need to flick the right hand paddle to encourage it to use top gear.

 

[Deleted member 65149]

Yesterday I went to Silverstone to drive a few laps in two cars that certainly weren't diesels - Aston Martin V8 Vantage and Ferrari 360 F1 Mondial (see my report at http://www.mbclub.co.uk/forums/mb-defectors-other-marques-forum/135728-excited.html

Afterwards, on the way to Bicester on the A43, a BMW 635d coupe came past me at a healthy but illegal, rate of knots. At the next roundabout I came up behind him after he'd got stuck behind some slower traffic. The outside lane cleared as we left the roundabout and a telltale puff of black smoke (not too bad I'll admit) told me that he was gunning it again. Out of interest, I too put pedal to the metal and comfortably stayed with him up to very naughty speeds . We did the same between a couple more roundabouts before I sensibly (for once in my life) eased off to protect my licence and possibly my life.

My point is that I keep hearing (from diesel lovers) all about how wonderful torque is, but it doesn't seem to make any real difference. I can only assume that it feels more lively because your brains are telling you that diesels should be as slow as busses and lorries. Sorry guys, you're going to have to try a lot harder to convince me that a clattery tickover and smelly fuel is better than a less frugal but beautiful sounding petrol engine.

 

[wilsodg]

What revs was it pulling at 70mph?

In 7th, mine seems to do about 39mph per 1000 revs, so 70 is about 1800 iirc. I recall max torque is at ~1900+

 

[st4]

Yesterday I went to Silverstone to drive a few laps in two cars that certainly weren't diesels - Aston Martin V8 Vantage and Ferrari 360 F1 Mondial (see my report at http://www.mbclub.co.uk/forums/mb-defectors-other-marques-forum/135728-excited.html

Afterwards, on the way to Bicester on the A43, a BMW 635d coupe came past me at a healthy but illegal, rate of knots. At the next roundabout I came up behind him after he'd got stuck behind some slower traffic. The outside lane cleared as we left the roundabout and a telltale puff of black smoke (not too bad I'll admit) told me that he was gunning it again. Out of interest, I too put pedal to the metal and comfortably stayed with him up to very naughty speeds . We did the same between a couple more roundabouts before I sensibly (for once in my life) eased off to protect my licence and possibly my life.

My point is that I keep hearing (from diesel lovers) all about how wonderful torque is, but it doesn't seem to make any real difference. I can only assume that it feels more lively because your brains are telling you that diesels should be as slow as busses and lorries. Sorry guys, you're going to have to try a lot harder to convince me that a clattery tickover and smelly fuel is better than a less frugal but beautiful sounding petrol engine.

The situation here is one where you were both really driving hard.

Its one of peak power. I suspect your car will corner harder than a 635D so will carry more speed into, and out of a roundabout. I would wager your car is also lighter than a 635d and peak power wise your car makes marginally more power than a 635d.

When in kickdown its power that counts, but in most real world situations its how the power is developed that counts.

To say do an overtake in one particular gear or two, the diesel will feel more relaxed, the petrol will need to drop one or more gears like for like to rev that much harder to make the peak power required.

The diesel has more torque lower down the rev range to make that matter and manouver but in out and out driving like this, its power that matters, cornering abililty and mass, all of which, I suspect are on your side.

I've got a clattery diesel, the noise really doesn't bother me, it doesn't excite me, but it acheives a decent level of power for not much outlay fuel wise, it means I can drive it further, and on roads like motorways where noise really isn't important, I can drive it more cheaply.

 

[gIzzE]

If was more than 1600rpm then you either lack the 7G+ or have it in Sport mode and need to flick the right hand paddle to encourage it to use top gear.

It is not the + 'box, but I think it was around 1600rpm as I remember looking down and thinking 'if only this was doing these revs at 80mph.'.


I will look next time.

 

[Dieselman]

It is not the + 'box, but I think it was around 1600rpm as I remember looking down and thinking 'if only this was doing these revs at 80mph.'.

It would probably be a bit short of power to battle against the wind resistance at 80mph.

If it's at 1600rpm at 70mph, that's 43.75mph/1000rpm, so at 4200rpm it would be doing 183mph, which is well above the power of the engine, so is an overdrive gear.
If it was 80mph at 1600 rpm, it would be 50mph/1000rmp, so at 4200 rpm would give 210mph. Way too over-geared.

 

[st4]

It would probably be a bit short of power to battle against the wind resistance at 80mph.

If it's at 1600rpm at 70mph, that's 43.75mph/1000rpm, so at 4200rpm it would be doing 183mph, which is well above the power of the engine, so is an overdrive gear.
If it was 80mph at 1600 rpm, it would be 50mph/1000rmp, so at 4200 rpm would give 210mph. Way too over-geared.

Imagine a dustbin turbo, some juicy high flow injectors, a straight through exhaust and a remap.

Sounds a barrel of laughs....

 

[mercmerc321]

Just driven a c220 cdi coupe in white i have to say found it quite noisy i hope the c350 cdi dont sound as noisy as this other wise its the petrol in favour

 

[Peter DLM]

The 350 CDi is much quieter Not as quiet as the Petrol though, obviously.

 

[mercmerc321]

Hope so

 

[Magoo]

The 350 CDi is much quieter Not as quiet as the Petrol though, obviously.

Be careful what you wish for.

The petrol is Über quiet. Some might say too quiet. But if refinement (& perhaps a little speed at times) is on your wish list at all, then without being reminded you're in a No 101 to the airport, the petrol will give you the satisfaction that diesel owners can only hope will come their way in their next car!

 

[NISFAN]

That article conveniently ignores resale value, as usual.

It also only works 'on paper'. Yes petrol engines can return good economy IF you drive them carefully....however anyone knows that you can very easily half the mpg of a petrol engine if you put your foot down.

Diesels are far more consistant in the MPG range, and therefore in every day driving.

 

[Magoo]

It also only works 'on paper'. Yes petrol engines can return good economy IF you drive them carefully....however anyone knows that you can very easily half the mpg of a petrol engine if you put your foot down.

Diesels are far more consistant in the MPG range, and therefore in every day driving.

Surely there's more to life than mpg?

 

[NISFAN]

Surely there's more to life than mpg?

Yeah, for me it is about range.....I can't stand filling up cars. So I guess I ask "surely there is more to life than standing in a fuel station queue".

I used to use a Subaru Sti that did about 23mpg for work. No problem with the amount of fuel it used cost wise(100 octane V power), but did have serious issues with the 230-250 miles per tank, I was literally filling the thing up every day. Was still one of the most fun cars I have ever owned for that occasional tight B road.

I would imagine that most of the people on here that ask the question about economy are the higher mileage drivers, and the 'who cares' responses normally come from low mileage drivers...... if you only do 5000 miles a year, fuel is going to be 10% of the importance to someone that does 50,000 miles a year.

 

[Dieselman]

I would imagine that most of the people on here that ask the question about economy are the higher mileage drivers, and the 'who cares' responses normally come from low mileage drivers...... if you only do 5000 miles a year, fuel is going to be 10% of the importance to someone that does 50,000 miles a year.

It would seem silly to spend more on fuel each month than the least cost...