Hammer1

You may be quoting something on a website (Renntech), but everything on the web is not always correct, just like facts posted to forums like this. The fact is that the GL350 has a stock torque of 455 kb-ft. That is from Mercedes not a website.

You are claiming that the GL350 engine when tuned by renntech only gains 9 ft-kb of torque? Come on, I believe Renntech can get more than 9 lb-ft of torque on their tune.

I believe I read somewhere on the Renntech site a while ago that they shoot for 20-25% increase in performance. That would raise the stock 455 kb-ft of the GL350 to about 570 kb-ft. I still think you are looking at the tuned numbers of the GL320 on the Renntech site (they must have a typo).

The 350GL may or may not tune up to the V8 550 when you fairly compare like model years, but the 350 still ends up plus or minus around 600 kb-ft (depending on which tuner site you want to believe). This is about what you are quoting for a tuned 550 (575 kb-ft).

Realize please, that I am not talking about 0-60, push back in the seats, freeway merging accelleration. Just torque, which is what pulls my Airstream trailer. The little 350 does a formidable job and get 14-17mpg while doing it, that's all.

BlownV8

Yeah, that's the ticket. Both Renntech and Kleeman have incorrect websites. LOL!

drgeeforce

My experience with a BTC will not be too encouraging for you. I bought a CPO with 29K mi and have had nothing but bad news as far as ownership. I had 3 fuel filters changed within 1 year because of the previous owners' fuel choices. Just recently I had the entire fuel system changed due to again, fuel problems at my cost. The FLW/ELW/CPO means nothing because MBUSA will blame you the owner for bad fuel. I recommend the 450/550 GL new or used, or the 350GL BTC (New only) because used MB diesel engines are ticking time bombs.

drgeeforce

Got any dyno pics to show any turbocharged gas engines get max torque @1600rpm? I know of some supercharged gassers getting torque @2200rpm. Twin Turbocharged gassers that I've seen get max torque @3500rpm.

http://www.dynocomp.com/data/detail/big_1089.jpg
http://oetuning.com/blog/wp-content/...-CA91-6002.jpg

drgeeforce

Anyone trying to compare a gas biturbo engine GL450/550 running 10-15 psi boost vs a single turbodiesel GL350 running 5-8psi boost, is silly. There's no comparison. That's like saying a 4.6L has more power than a 3.0L.... no duh.
Throw 5,000 lbs. behind a 450/550, sure, they'll beat you 0-60, but you will ALWAYS pass them at the gas station.

drgeeforce

Nine of 10 diesel cars and trucks studied by the University of Michigan had better five-year residual value than their gas-engine counterparts and half were at least 10 percentage points better, led by the Mercedes-Benz GL with a 39% residual value advantage over the gas GL. It is also our favorite full-size SUV. What’s more, with the GL, the diesel version is the cheapest GL model.
http://www.extremetech.com/extreme/1...he-environment

BlownV8

You do know why MB's get the max torque at such a low rpm, right? They use very small turbos that spool almost instantly. The stock GL550 produces max torque of 516 lb-ft at 1800 RPM. http://www.autoweek.com/article/2013...IEWS/130539958

The stock MB M275 V12 bi-turbo also pruduces max torque of 590 lb-ft by 1,800 RPM.
Also, see the Bently's max torque at 1,600 rpms: http://media.caranddriver.com/files/...y-coupes-1.pdf

Any more questions?

Ed Wolcott

I have owned several diesels over the last few years, and they do not like being driven short distances in cold climates. This results in heavy fuel consumption and short oil life. If this is most of your driving you would be ahead with a gas vehicle. If you have to use diesels for this type of service, frequent oil changes are a necessity, I would change the oil every 5000 miles. I have encountered out of warranty issues on both diesels and gas engine equipped vehicles--good maintenance and a early detection of problems is about the only thing you can do to reduce these. In both gas and diesel vehicles, these problems can be costly, at $100 or more per hour for a mechanic's labor, it does not take long for costs to add up.

The new Bluetech diesels should be more reliable, because they take care of the nitrogen oxide issues with a catalytic converter, rather than with Exhaust Gas Recirculation (EGR). EGR in diesels is bad news--the soot in the exhaust gets fed back through the diesel, and when this is combined with the oil fumes being fed into the engine, this results in manifold and coolers getting a heavy layer soot mixed with oil on the inside. Elimination of EGR should eliminate these problems.

BlownV8

NOX is a generic term for mono-nitrogen oxides: nitric oxide and nitrogen dioxide. There is a little bit of nitrous oxide too.

ymmv

The thing is, when I open up the GL550, I don't think I want a ounce more power -- it already torque-steers obscenely -- I just want it to be much, much more direct, smooth and linear in throttle response. That's on CA 91 "California water." The last thing I want to do is ask that power train to load up and throw a rod trying to propel that 6000lb vehicle around.
I don't mean to say that I think 430hp/520tq is a lot or that the 4.6l v8 twin turbo is a handful (one of my road cars is a 520hp 3.6l 911 turbo, my track car is a 8800 rpm 450hp 911) but seriously, this thing gets up and goes. The only thing it lacks is refinement in the power delivery. I've drive 20K+ miles in a GL350 bluetec and it was as smooth as a proverbial baby's ... torque notwithstanding, the only thing it lacked was the oomph to "holeshot" from a standing start ... once you learned to get it in a tall gear, build boost and let it work, it was very capable.
I chose the 550 this time because it was not that much more than the equivalently equipped 350. Of course, that can change on resale, but I try not to buy with too much forethought to the next owner.

somersetjon

This is such a great thread!!


In all seriousness, I've owned one performance diesel and sold it quickly at a big loss.


As a previous post states you have to keep the engine in the high torque areas, which means changing gear well before the red line, they run out of puff. In my experience the engine/gearbox mappings with the auto box are totally wrong as on full throttle they don't change until the red line when they should have changed a while ago!


My diesel Audi (3.0TDi BiTurbo 313HP) was even further flawed with the kick down algorithm, as it would change to too low a gear, sky the revs, have no go left and then change again - all of which would leave you struggling to overtake a car having put yourself on the wrong side of the road.


Obviously the GL350BT is not a racer so these points matter less, but with the gas engine you get full go until the red line, change and go again - simples.

Hammer1

I guess they both must be wrong then if, you are quoting that the GL350 only ends up with 465 Lb-Ft of torque after the tune. The GL 350 starts with a stock 455 Lb-Ft. And that is the ticket.

For the last time, you are looking on the Renntech site at the old GL320 or they haven't updated their site. PLEASE CLICK ON THE ATTACHMENT BELOW. (From the Merceds Benz site)

Cheers.

infamily

I agree.
Renntech site info is for older gl 350 here is there info- torque goes from 389 to 464


RENNtech ECU Upgrade for GL 350 (X164- 253 HP / 464 TQ)

$1,295

Click to view images
SKU: ECU:54.164.GL350BLUE
RENNtech has been at the forefront of ECU tuning since electronic engine management started to show up in vehicles during the mid 1980's! Our experience, countless hours of in house research, development and exhaustive testing ensure that our proprietary ECU upgrade offers incredible performance gains and rock solid daily driver reliability.
RENNtech tuning software for Mercedes offers significant gains in horsepower and torque across the vehicles entire power band. By modifying ignition timing and throttle mapping, optimizing air/ fuel ratios, increasing the engines rev limiter and modifying boost mapping for turbo charged vehicles, RENNtech performance software unleashes your Mercedes true potential.
GL 350 BlueTec (X164) Stock Performance:
230 HP / 389 LB-FT
Gains:
253 HP / 464 LB-FT

BlownV8

Here is the one for the updated engine from Renntech's site. It is the updated one for the ML 166 but it uses the same engine as the GL 166. It takes the torque from
455 lb-ft to 485 lb-ft. Still not what you expected was it?

http://www.renntechmercedes.com/www/node/969
240 HP / 455 LB-FT
Gains:

260 HP / 485 LB-FT
Price: $1,295

whitecoatgeek

I finally had a chance to test drive a GL350 again. I had to drive 2 hours to an out of town MB dealer who had one in stock. It's little slow for what I am used to but perfectly acceptable. I am going to stick with 350 and finalized the order. Added lighting package and chrome accessory package. Delivery expected in mid april. Thanks for all your help

BlownV8

Lot's of issues with the diesel engine too. You may want to read some posts on the 164 GL forum if you want to keep it past the warranty period.

Todd in PA

Just saying, Mercedes Benz has tons of Diesel experience. I have never read anywhere how unreliable Europe's diesel fleet is.

emilner

I don't believe he is getting an older GL, he is looking new. There has not been much evidence of issues with the newer 350's.

I went ahead and did a Race Chip for my 350. They claim +60hp and +118lbs tq for $349. There has been some testing saying that the claims are pretty close to accurate.

http://www.racechip-usa.com/media/racechip_review.pdf

I will say it is completely unnoticeable when normally driving until you get in it. I only installed it this morning but so far I'm quite pleased with the power increase. I was pleasantly surprised by the 350 stock, but now it really gets up and goes when you floor it. I don't think it is up 118lbs of tq but it's certainly more powerful than stock, and for $349 shipped its a steal....

PunjabiM3

I assume this voids your warranty.

emilner

Yes, with the following two assumptions:
A- If it causes the problem.
B- I'm dumb enough to leave it on the truck.

BlownV8

Same engine - different turbo. Not a whole lot of difference. MB's are very consistent. It's just a matter of time and mileage before you see the same issues.

This is interesting considering the two best MB tuners in the industry, Renntech and Kleeman, only report a 20 hp increase with their chips. No way would I put this on my GL or believe they are getting these results without dyno testing.

RayPag

Group,


We took over a lease on an '09 ML 320 BT that had 30k miles on it.
After 3 years, we now have 92k on it. It's my wife's car with two active kids.


The only issue was the fuel pump needed to be replaced. The second one for this car. It took them 4-5 visits to narrow it down, even though I told them that it is likely to be the fuel pump. They have to go through their red tape first - which took a lot of visits.


Other than that, it is a great SUV. We have the warranty to 135k, so soon after we hit that I'll put it up for sale.


The mileage is great, as mentioned.
Two major drawbacks are the AdBlue re-fill and run flat tires.


MB likes to flush the AdBlue when in for the A and B services. The fluid and labor (they reset the computer too) runs $300-$400. I top it off myself between services for a lot less.


The tires don't last more than 20k miles for us and the with run flats you can easily exceed $1,250 to replace all four.


So when you add the extra costs to the mileages savings, it is close to a wash. I like to believe I'm still ahead some.


One nice thing, MB R and D currently has the car in their Detroit R and D center to test its emissions.


They came with a new '14 GL 350 BT on a flatbed for us to use for our
troubles. They put our ML on their flat bed and I'm told will run a few tests on in and put little miles on it. And we'll get a Visa Gift Card when done. Nice perks. My wife now says that they can take their time with our ML, as she loves the loaded GL we get to have for a few weeks....


Ray

emilner

Renntech is seeing similar power gains. They have the old X164 information on their site. Look at the stock numbers they claim the truck puts out, they are identical to the X164, not the X166.

You don't need to put it on your truck, that's of no concern to me. It does work however, and works quite well actually. In the BMW forums there are quite a few people who have had great success with it. It's not some random never heard of company....

emilner

The GL350 does not have runflats, even though my dealer insisted it did even after I showed them the tires were in fact regular ones. They also insisted it didn't have a spare tire, when I opened the hatch and showed the spare to them they just looked all confused. Dealers are quite amazing....

BlownV8

Ok, what you typed did not make any sense but I think I know what you were trying to say. The X166 is the new model not the old one.

Either way, Renntech does have the updated tune for the W166 which uses the same engine as the GL. They Gain 20 hp and 30 lb-ft of torque for $1,295. This is exactly what Kleeman gains too.

I would be very skeptical of the other company that is gaining 60+ Hp and 118 lb-ft of torque for $349 when the others are gaining a fraction of that power. I would want to see an independent dyno before I would trust the claims.


http://www.renntechmercedes.com/www/node/969
240 HP / 455 LB-FT
Gains:

260 HP / 485 LB-FT
Price: $1,295