DubVBenz

Regardless of tuned or not, but the M278s have lots of cooling plumbing issues around 100K. Only a few grand to replace, but it's all plastic bull**** that fails regardless of model. My M276 turbo apparently has similar design flaws but is easier to replace due to packaging. I do not know if later versions of the M278 improved that, but I doubt it.

Left Coast Geek

my personal thing about performance tuned cars is, if you drive them to their capabilities you WILL be breaking and wearing stuff out a lot faster and on a car like a E550, that WILL be expensive. long as you're going into it realizing that the cost of the performance upgrades was just the down payment, then cool. me, when buying a used cars, *ANY* performance upgrades are an immediate turnoff because I want a reliable daily driver.

KEY08

I’ve come to my own conclusion that the M278 in the E550 is enough of a beast that additional tuning is not necessary unless you are drag racing it for times. We know from dyno tests that the stock HP is not 403, but more like 430. It is down-rated. My Shelby GT350 had 527HP and the E550 felt every bit as fast from a dig up to about 45-50 where the Shelby would run away and hide. Two different cars for sure and automatic vs manual, but my conclusion for me personally was the gains in tuning the E550 only risked damage and wouldn’t improve my personal enjoyment of the car. I know the OP wasn’t looking for this type of discussion of to tune or not to tune, but this E550 is a very special car right out of the box and people unfamiliar with it can benefit from owner’s opinions.

Blkvip

yup. 2 lines so far broke on me. 1 i lightly hit other could start to see coolant residue building up. the V8 gives no room. while the lines are cheap labor isnt lol

diesel_dan

Thanks folks for keeping the comments coming! I still have not thrown the "mild" stage 1 on the car - I agree that this car is "special" and has a lot of GO just stock (there is a reason MB only had the 278 in the E for 3 years - it either sucked away E63 sales or was embarrassing S-class owners...). We had a number of things updated under warranty: timing tensioners, engine/trans mounts, etc.

I was going to throw the tune on and didn't have a charger that put out the constant voltage that OEtuning recommended, so I held off. I now have a replacement charger with the constant voltage setting (power supply), so I think I'll give it a shot... And yes I know the old adage of: If you want to Play, you have to be willing to Pay... Sounds like the M278 can handle some Play without too much Pay'in...

PekkaH

Yes what ever reliable stage1 tune will give you smile on your face and its not gonna brake anything if you don't drive like a mad man all the time 24/7

S. Madman

Did someone mention my name?

I do have a tune for 3 years now.

Problems? Yeah rubber mounts, axles (because of mounts). Engine wise, nah.

Just change your oil at 5k, and you will be fine.

I also upgraded the brake rotors to Brembo, because adding 100hp and 200tq makes things appear sooner.

The stock Zimmermans where not up to the task.

PekkaH

I haven't broke anything yet and also tuned three years and drive quite hard. My M278 is like stage 3 level now. I can recommend Brembo also.

Beat the car and my best runs are:
0-60mph 3.16s,
1/8 mile 7.11s trap 102,3mph
1/4 mile 10.95s trap 128,7mph

So people can drive safe with stage1 tunes from any reliable tuner. If car broke down because a stage 1 tune there were something wrong on the car before tune. that's my opinion.

KEY08

wow! Those are impressive numbers. Nice job!
The potential of this heavy sedan beyond its stock quick performance is pretty incredible.

DubVBenz

making me regret my decision to go with the E400!

KEY08

Nah, you have a great car! I think a stage 1 Eurocharged tune will boost that engine from 333HP to 480HP . $1299

Chevota

I'm pretty sure OE Tune sets the speed to 224mph? The lower speed torque limitations are adjusted up a bit but I don't think it does anything, meaning I can exceed the settings so I think it's redundant. There's misc things like that in the ECU that don't actually do anything.
Plus it's the tranny that does the real limiting, which it does in 1st through 3rd by closing the throttle on you. You're not free of it until 4th but then you're going is like 130mph, so annoying... To fix that you have to buy a trans tune, which last I checked was $1800 and you had to send them your trans computer which is inside the tranny. So even if you're willing to pull it out it's still a good week without your car. I'm waiting for the ability to tune via the OBD port. Those tunes don't eliminate the limiter, they just raise it, so if you want more power you'd have to pull it out and send it in again. Screw that.
I ended up buying HP Tuners to tune the engine myself, and if I could go back in time I would tell myself to do that instead of the OE. So that was a $1k lesson and $ I could've put elsewhere. So basically I want the same ability to tinker with the tranny, because I hate the trans. I think # 1 is I want it to shift when I say, not when it feels like it. The other day I counted and it took thirty shift commands to get from 2nd to 4th. Yes, 30, three zero, to go two gears. If I shift twice I expect two gears, why is this so difficult?
With HP you can also stop that super annoying loud cold idle. You can turn the cooling fan on much earlier so it's not borderline overheating all the time, and bump the idle timing to do the same. Change the way the gas pedal commands the power, like that stupid Pedal Commander they sell except you have substantially more adjust-ability. But mostly it's about the power... It's a pita to figure out how to use it in detail, but duplicating a simple tune like the OE is easy. And it's cheaper, and even more so for the next car or a friends car. Plus you get a program to record what the car is doing, like an app like Torque Pro does but it's redonkulously better. Fyi...