Has your 123 increased your MPG?

[hauser]

It's really too soon for me to tell but I just filled up and noticed a slight increase in MPG.  In mixed driving, city, highway and a bit of spirited driving I calculated an extra 2 mpg.  I'll continue to monitor as time goes by.  BTW it was all top down driving.

[Atazman]

What kind of mpg did you get after the 123 installation?  My 1st tank after installing the 123 was 14.5 mpg.......all around city.  Can't say it was any better than what I got before.  On my 2nd tank now, but have been doing lots of idling and making adjustments, so not a good test.  Anxious to fill up and hit the highway to see what happens.  The car is running very good, so I'll be disappointed if mileage does not improve.   Let me know what you are getting.

[Cees Klumper]

I haven't noticed a difference yet, but I'll keep an eye out this summer; it might have improved somewhat. In my 11 years of ownership, I've consistently been running about 18 MPG, mostly highway use at an average speed of about 75 MPH (the speed makes a BIG difference BTW).

[mdsalemi]

If the 123 introduces a new "state of tune" where the ignition (timing and stability) is better than before, you should see some MPG increase.  That increase is more related to the car running better than the 123 itself.  Given a new distributor, new ignition components, and a well tuned and running car--I don't think suddenly swapping that perfectly working stuff for a 123 will yield an increase.  Of course, the 123 should make maintenance of your new running condition easier to maintain.

Hauser, remember you had ignition issues, and hopefully they went away--so now you have a better running car which should give you better MPG than one that isn't running well.

Cees is so right--speed is a big issue.  My daily driver has a built in MPG gauge.  My average on the highway at 75 MPH average is about 23.5 MPG.  If I fill up, reset the MPG gauge, and sustain 55 MPH on level ground I'll maintain over 32+ MPG.  As soon as I get to a hill, or begin highway speeds, my MPG average falls quickly.

[hauser]

Mike, I have always checked my MPG periodically.  If anything it's an indicator that things are working properly.  When I had my Crane installed my car delivered an average (soft top up or topless) 17mpg.  Now that I have the 123 I averaged 19 mpg.  Coincidence?  I don't know as it's still too soon to tell. 

My best overall with the hard top on was on a round trip to St. Augustine, with the Crane, delivered about 23 mpg.  This particular trip took me through small towns and two lane roads.  The average speed was about 55 mph with short runs at 75 mph.  I wasn't trying to hyper mile it, it's just that road conditions were the major factor in how fast or how slow I drove. 

I have always found that the steadier the speed and the longer the trip will yield the best economy figures.



 

[Atazman]

Just did a trip........my first after installing the 123 ignition.  A total of 274 miles (about 50 miles city driving; the rest freeway spped of about 65 mph) and I averaged 18.5 mpg.  Can't really say that this is improved over what I had been getting.

[Benz Dr.]

I get a consistant 10 liters per 100 KM.  That equates to 23.5 USG or 28.3 IMP. I have not checked the distance with GPS. As taken from trip meter in car.

' 66 230SL, AKA '' The red rocket. ''

Engine: 2.5 L with 230SL cam,  180 HP
early 230SL exhaust headers
180 PSI compression
polished and ported head, new valves and springs
ZF 5 speed trans
 I K ohm spark plug leads, W9DCo plugs, .032 gap
300SE dual point distributor, 52 degrees dwell angle, BMW Bosch distributor cap
red coil, 26 KV, 1.8 ohm ballast resistor
tires set to 32 PSI
standard ( for 5 speed cars ) 4.08 disc brake rear axel, synthetic lubes throught the whole car
steady 3,000 RPM - roughly 55 - 60 MPH.
89 - 92 octaine fuel. Most is 89 with the odd splash of 94
Ran 650 KM and used 65.2 liters on last tank. I never use the fuel gage....

 All stock vintage parts from the 60's except maybe the coil which I've seen on old VW's so they were around back then - not sure what year though.

[mdsalemi]

Dan,

That is truly astounding mileage, in my estimation.

I have rarely achieved much more than 16 MPG US.  Only premium fuel, 92+ octane.  The type of driving I check it on is highway, such as the Blacklick trips, average about 70 MPH.  Of course I have an automatic, that's probably excuse for a few MPG, but not 7.

To get 23+ MPG is pretty good, and probably better than most.

Any idea why?

[J. Huber]

To get 23+ MPG is pretty good, and probably better than most.
...

Certainly better than mine. A few years back I went on a road trip and logging purely straight-up highway miles, I was well up over 20 US MPG. However, typical mileage for my area was more like 16-17. Then something happened, not sure what. I have been at 13-14 or so for two years -- during which I have tuned things, played around with mixture, etc. Car runs as it always has (good!) but 13-14 has taken over.

PS One thing I have yet to check is CO... don't have access to an analyzer... I suspect I am high. (so does wife  ...)

[Naj ✝︎]

300SE dual point distributor, 52 degrees dwell angle, BMW Bosch distributor cap

Hello, Dan,

Is that a vacuum advance distributor?

naj

[Benz Dr.]

Yes, the 300SE distrbutor is vacuum advance. It messed me up at first until I figured out what was wrong and then I got the correct throttle valve housing instead of the vacuum retard that was on the engine at the time. This thing throws a wicked spark for a points and coil system. The higher the dwell angle the longer the coil has to build up a charge. You can only get 52 degrees ( which this one runs at ) with dual point. This unit has two sets of points that feed three plugs each. The cam only has three lobes so the points open half as often as a regular unit. At 3,000 RPM the points are moving like the engine is only running 1,500 RPM. They last a VERY long time in these units - at least 10 years. Same points as used in 6.3 and 600.

 I did a test with GPS today. At about 3100 RPM I was running 100 KPH ( 62 mph ) My speedo says much higher than that at about 115 KPH.

 We tested the trip meter but I didn't drive that far. At 5 KM the real distance driven is more like 4.4 KM so I'm showing about 12% higher than actually driven. This could be closer to 15% which is roughly the amount the 5 speed over drives the drive shaft. I suspect that my speedo is set for the 4.08 diff without the 5 speed figured in.
So, I'm probably more around 25 - 25.5 MPG ( IMP ) which is still pretty good. Without the 5 speed I'd be down around 21 - 22 MPG at the same road speed ( still not too bad ) so that's where a lot of the milage comes from. The rest is a combination of tuning tricks and a lot of research figuring out what works and what doesn't.

Anyone want to hear about the 600 I picked up last month?

[mdsalemi]

I've been told that the reason why a 600 was made so large, is you need space to take your mechanic with you at all times.  Did the car come with its mechanic?

[Naj ✝︎]

Yes, the 300SE distrbutor is vacuum advance.

Anyone want to hear about the 600 I picked up last month?

Thanks Dan,

I'm a beleiver in vacuum advance too.
My 280 is running on a distributor from a M 110 engine and a 230 SL throttle body.

I like stories of the 600 and M100 engines too.

naj

[hauser]

I've been told that the reason why a 600 was made so large, is you need space to take your mechanic with you at all times.  Did the car come with its mechanic?

Not sure if you know this but the toolkit came with a hammer.  If it don't work hit it a couple times with the hammer!

[Benz Dr.]

The 600 is way over the top from every angle. It has a hydrolic system that runs the windows, seats, front air flaps, shock dampening, trunck lid, E brake release, brake master cylinder and probably a bunch of other stuff I haven't figured out yet.
Everything is trimmed in chrome and wood inside - it's everywhere. All the finest materials and everything done perfectly.
The front floors have copper sheets under each floor mat. We figured out that the AC lines run under these copper panels. With the AC on it cools the front floors because the exhaust runs right up against the floor boards on the bottom side of the car and things would get pretty hot around the floors otherwise.
The cooling fan for the engine is a piece of mechanical art work and probably just as exspensive. Engine oil pressure runs through the center of the pump and into a torque converter that spins the fan - all temp controlled of course. The engine is very similar to the 6.3. All I've needed to do was change the oil and filter. It needs no major engine tunning.

Car is 100% rust free. Only 68,000 miles. It was used as a movie car in Toronto for several years then someone started a complete restoration on it. All the chrome was done with boxes of NOS parts were ready to be installed. It was ready to be painted and the guy died - all of the masking tape was still on the car when we picked it up.

I'm working on the air suspension which is fairly straight forward and it's actually easier to change an air bag than a conventional coil spring. I'm sure I'll need to have the air valves looked at as well.
Even though the car is 5,800 lbs it will still do zero to 100 KMPH in about 10 seconds. 300 HP engine with 450 ftlbs of torque.

[Naj ✝︎]

Hi, Dan,

This is a great resource for the 600 (if you don't already know it)

http://www.m-100.cc/forum/

naj

[mdsalemi]

Dan, sounds like a find!  Enjoy it.  It is the OTHER of Paul Bracq's masterpieces.  Is yours a short or long wheel base?  Isn't one of the extremely rare Landaulet models is it?

In addtion to the M100 group, there is this guy Karl Middlehauve http://www.mbgrand600.com/ in Wisconsin who, though slowing down a bit because of age I'm told, is to the 600 what Gernold is to the W113.  Dedicated to only that model.

There is a guy in Toronto who has a 600; he drove it on the Route 66 tour a few years ago (MBCA) and even AUTOCROSSED it at Starfest in 2006.  See below, photo from Ken Rockwell Photography.  What a hoot.

Make sure you get/make some official looking flag holders for the front wings so you look stately and important when driving around Sombra.  Maybe you'll be known as "King Dan and Lady Shelley"

[Benz Dr.]

This car is a SWB model, black on black.

 The guy from Toronto is Mike, can't remember his last name. He had his car over to my place a few tears ago. That one is a fairly rare LWB that came from Tokyo, either as an embassy car or a corporate piece of jewlery.
This car had a dedicated driver so it had the glass divider with intercom between the driver and pasengers. The front seats were done in leather but the back were all corduroy. A readlly LARGE car.

I'm very aware of all the other clubs and what they're doing. I've talked the Karl M. a few times. This is a very small fraternity within the MB family. Either you know the other players or you're heard of them.

So, is 25 + miles per gallon above average?

[mdsalemi]

Based on my experience, 25 MPG is well above average.  I don't think I'd get that going down a greased hill in a hurricane.  Others here are mostly under 20. 

[Benz Dr.]

I'm going on the Imperial gallon which is about 20% bigger than a US gallon. This probably in the range of 11 liters per 100 KM - / + 5%.

  Do I get a prize or something?

[graphic66]

C'mon Doc nobody ever uses Imperial gallons, that's just plain goofy. MPG is not imperial gallons, I believe that would be MPIG. You are getting about the same mileage every body gets with these cars 18-20 MPG.

[Benz Dr.]

You think that's goofy? Try this; liters per acre, using US gallons, in an imperial gallon tank. That's what we use for spraying our soya beans.

  No....... I'm getting at least 21.5 miles per whimpy US gallon.