baldmike73

tunes from the big guys are all around 2K

but look into Weistec, EuroCharged, LogicTuning - so many other good tuners you can't go wrong with a good tune these days - and the new V6 needs more power -

i am waiting to get my 350 tuned here shortly -

BlownV8

You really can get that much from a good tune. Been there done that and posted through dyno charts. Not on this engine but on a previous V12 biturbo. The biturbo v8 is even more mod friendly.

ioman

Whats your gas mileage now?

w220430

The thing I always wonder about tunes is, how do they affect the overall drivetrain and the transmission? Will they be able to handle the additional horsepower and torque without being damaged?

The tuning companies will of course say "Yes no problem!!!" but what is the real world experience regarding any drivetrain/transmission damage or premature wear?

wheelsloose

Have been away from the site for awhile but yes the tune is still great and going strong with no issues 36,000 miles later. Only problem I just had, not sure if it is tune related or not, was I took it in for basic service and finally needed my emissions sticker updated to renew my registration (finally past my 2yr exemption for new cars in TX) and it didn't pass emissions. Dealer thinks it was related to a bad O2 sensor and possibly new updates on ECU that they needed to install to get it to read and pass correctly. Low and behold they ended up having to reflashed my ECU with the new software updates and overwrote the Renntech flash. GL feels so slow and sluggish again to me now. Have already contacted Renntech and going to send it back to them next week and they will reflash for me for free.

wheelsloose

I beg to differ. These newer twin-turbo V8s are very tunable and receptive to reflashes and can see significant gains from tunes alone. My 2012 CLS63 came with 515HP and all I did was remove the resonator and have Renntech flash it and I ended up with 660-672HP, depending on the dyno and temperature outside and I dyno'd three different times. My baseline dynos were both slightly higher than the stock HP rating of 515 and came in at 521 and 516 on two different dynos.

scottmcdaniel1

that's interesting. i'd be interested to see what true hp numbers a biturbo 6 puts down in the 2015 GL450 vs those numbers after getting a Renntech tune...

Mike450

OEtunes claims 400whp 400wtq with their ecu flash.

scottmcdaniel1

i've seen that OE claims 362hp boosted to 448hp and torque from 369lb-ft to 533lb-ft for $1,200

Renntech claims peak hp of 501 and peak torque of 576 for $2,800

the question(s): are the claims fairly accurate on the peak side and, if they are, is the Renntech gain of 50hp and 40lb-ft worth the extra $1,600??

BlownV8

From my experience, Renntech under promises and over delivers.

fabbrisd1

In this instance - RennTech tune - although pricey - I have recent nightmares with OE Tune on a GL550 and a CLS550 ... they "made good" on a stock ECU replacement for the CLS550 which got fried on their side - we both vehicles back to OE programming then upgraded with both with RennTech

Silver0066

From Renntech's website:

GL 450 (X166- M278 Biturbo Engine) Stock Performance:

• 362 HP @ 5,250 RPM; 406 LB-FT @ 1,800 RPM
• Note: Mercedes M278 engine performance when measured obtains higher numbers that rated from factory.

Modified Performance:

• 501 HP @ 4900 RPM; 576 LB-FT @ 4100 RPM

What is Renntech's torque at 1800 RPM? In other words, I would like to see an like for like comparison.