Driving the 6.9 daily

[Styria]

Hi BenzBoy, that episode just proves that I do not mollycuddle my Gleaming Beauty if the need arises. That time, a changing of lanes accompanied by a significant puff of black smoke indicated that Michel in his 560 threw down the gauntlet - I just had to respond, didn't I ?

Anyway, there is a difference between 'hard' and 'fast' driving - I am quite happy to get there 'slowly' as I believe that one can cause more wear and tear in the first 100 meters (if you flog it) or 10 kilometers of normal, swift driving.

S-Class - interesting observations. In my view, the 'smallish' tyres that you use would definitely be instrumental in the car letting go in the back. Mind you, I do think that this trait is a characteristic of 6.9 handling. You get initial understeer which then soon changes to oversteer with the rear wanting to let go in a fairly controlled manner - I found this out at Eastern Creek, one of Sydney's racetracks and, as you feed a little more power through, the car will continue in a fairly predictable oversteer manner. Incidentally, my 235/45/18" Nankangs really provide a safe and very stable enviroment under all driving conditions. I don't think I'd like to go back to standard size tyres.

At 120, Gleaming Beauty is beautifully quiet, and also very stable. In fact, it loves 120 - 130 on undulating, and somewhat curvish secondary country roads. You do need to have your wits about you, but I always get the feeling that the car is communicating with me - it's almost like a co-driver and lets you know what it is capable of. Okay, you can all have a laugh, but honestly that's my impression of open road, fast cruising where the long arm of the law is not likely to interfere with you. Regards Styria

 

[s class]

the sense of communication with the driver - thats what I've always loved about my 280SE. I accept the 6.9 may do likewise, but I really don't have enough experience with it yet.

 

[Michel]

the sense of communication with the driver - thats what I've always loved about my 280SE. I accept the 6.9 may do likewise, but I really don't have enough experience with it yet.

you need to learn to talk to each other

 

[Bandolero]

S Class,
By running 205/70/14 your speedo will over-read by 2.9%.
The standard tyres for a 6.9 were 215/70/14.
The 205s were the standard tyres for the rest of the V8s.
The 225/60/15s will make your speedo over-read by only .9% so they will be perfect. Will handle better as well with the lower profile.

 

[Michel]

S Class,
The 225/60/15s will make your speedo over-read by only .9% so they will be perfect. Will handle better as well with the lower profile.

What is the correct 15inch tyre 007?

 

[Bandolero]

The 225/60/15 is certainly close enough.
It depends on the width of the rims as well.
225 is great for 7-8" rims.

http://www.miata.net/garage/tirecalc.html

This is the calculator I use....works well.

225/60/15 for 15x7" rims and 225/55/16 for 16x8" rims.

A 350 or 450 used 205s, so 215/60/15 and 215/55/16 would be the equivalent tyres to use on 7" rims.

 

[alabbasi]

I try to drive my 6.9's as close to daily as possible (when you have more then 4 cars). I get about 200 to 230 miles from 23 (US) Gallons. A few months ago a full tank would cost $100 US. Now it's about 1/2 that.

I guess that means I should take the 6.9 out more and enjoy it while it lasts.

 

[BAR]

I had thought to develop a 'new' system for the V8's based on a Modern Motronic engine management system.

The objectives were to improve power and at the same time improve fuel economy.

Basic maths on the project revealed that it would be less costly simply to swap the old steel V8 with a modern alloy V8 [even from a later model Mercedes].

So for now and perhaps until it is sent to the scrap heap I shall simply enjoy driving the 'binge drinker' - Gas Guzzler is too lightweight a term.

 

[alabbasi]

I just paid $1.85 / gallon to fill up my 6.9. First time in Ages that I have seen a $40 full tank. I'm quite happy

 

[Michel]

I haven't driven, let alone laid eyes on my 690SEL since before I went away.
I hope this weekend at Oran Park Raceway will make it up to her.. ;-)

 

[Styria]

Hi Alabbasi, that is cheap petrol ! I see that your consumption is quite diabolical - meaning 'very high' - locally, at the moment (Sydney, that is), one litre is about $1.30 - 95 octane variety....in gallon terms, say about five bucks a gallon.

Since the valve grind and de-coke, I've not carried out a fuel consumption test. I am giving the engine every chance to 'close up" before I test the amount of fuel used. In my view, it will need at least 5000 kilometers to seal properly. Regards Styria

 

[alabbasi]

Hi Alabbasi, that is cheap petrol ! I see that your consumption is quite diabolical

Styria

I'm not gentle on my 6.9s (or any other car), I boot that thing around at every opportunity so I don't expect good mileage. I get similar mileage from both my 6.9's so I suspect it's not out of the ordinary.

I have taken it for long highway runs and the mileage improves to 300miles + for a tank.

 

[Styria]

Hi Alabbasi,

well yes, I can do a bit better than that. Perhaps the fact that Gleaming Beauty runs the high compression "dirty" engine may certainly help with consumption. As I have previously said, the difference between clean and dirty engine is round about 3 miles per gallon.

I know for a fact that my 6.9 is more frugal than a certain, well known, 350SE. I looked at the consumption figures one day in Canberra. At that time, I think that the 6.9 consumption was very similar to a 560SEL driven by the Prince of where ? Libya, Oman, Egypt ? Regards tyria

 

[BenzBoy]

You can't take any notice of consumption figures in Canberra, Styria. They are like the Consumer Price Index and vary according to the cost of bananas. Now every time you talk of Your Gleaming Beauty, the following springs to mind. Is this the one you mean?



Regards,
BenzBoy

 

[Michel]

Hi Alabbasi,

well yes, I can do a bit better than that. Perhaps the fact that Gleaming Beauty runs the high compression "dirty" engine may certainly help with consumption. As I have previously said, the difference between clean and dirty engine is round about 3 miles per gallon.

I know for a fact that my 6.9 is more frugal than a certain, well known, 350SE. I looked at the consumption figures one day in Canberra. At that time, I think that the 6.9 consumption was very similar to a 560SEL driven by the Prince of where ? Libya, Oman, Egypt ? Regards tyria

Godfather, you need another drink....

That was what the 560 you were trying to keep up with...

 

[Oversize]

I wonder if Motec's Motec system will improve fuel consumption?? I suppose on a stroked engine it'll be hard to tell....

 

[Tony66_au]

The rule of thumb for large old high displacement engines is that the consumption is directly proportionate to the weight of your right foot.

Many years ago (27 ish) I had an 1170 kg Ute with a stroked 440 cubic inch V8 with an auto box behind it and 3 x 4 bbl Carter carbs ontop.

It would get roughly 4 km per litre Pump fuel and maybe 6 km running Avgas, it had no accessories to speak of and could not be driven in the wet .

If I drove it hard (Industrial Ave Thomastown or Cherry lane Laverton) the thing sucked more juice than a loaded semi @ 2 miles per litre.

After this monster everything else paled to insignificance lol

So these days I have a small runabout with incredible economy and creature comforts which offsets the consumption of my Range Rovers and Mercedes.

As for consumption of the V8 Benz's?

No higher than my 3.5 lt twin carbed 4 speed manual Rangie so its actually quite good.

And if i have a tight week?

Diahatsu time! (Oh the shame...)

 

[motec 6.9]

Hi Mark and Tony i have commented before but the fuel consumption with the motec system is about 12 to 14 litres to the 100 so about a 10 percent improvement over the standard bosch k jet

 

[Tony66_au]

So about $15 per tank saving........... (Based on $1.55 Premium ULP and a 98 Lt fill)

The big qweshtyun.........................

Does it go harder?

 

[Tony66_au]

The more and more i learn about these big old lumps and how they are fed, the more I see the D jet system as a better solution for Enthusiasts because apart from the air/fuel metering the system most closely resembles Fuel injection as I know it.

I was quite daunted by my lack of familiarity with Mercedes feeding habits and yet when i got stuck into it the system actually makes a lot of sense for reliability and accuracy of the fuel delivery.

I've got to admit that once the concept "clicked" into my overcrowded brain I powered ahead and solved the problems I've seen many struggle with surrounding the AAV.

And that late night/early morning when I turned the key to check my handywork and found it worked as intended I did a very exuberant happy dance (Probably the fumes) and was caught by my Wife (@ 2am lol) patting myself on the back exclaiming what a genius I am.