BETO

I have a Prius, and that's only if the engine is not turning, as soon as you hit the gas pedal the gas engine starts working. Nice try

gordongl450

Thanks for the great discussion. It was helpful to me.

Seems like people would say turbo lag is the reason the GL320 CDI is slow off the line.

If that is the case, then what is the benefit of the hypothetical GL420 with a V8 diesel that everyone is hoping for? (But it seems, will never get) Won't that still have turbo lag and be slow at the start?

Would you say that the Mercedes engineers were correct when they decided that the V6 CDI was a big enough engine to push the GL truck around adequately? After all, SUV's are not sport cars, they just have to get you and a lot of stuff from point A to point B.

Thanks

StevethePilot

First off, the 420's only hypothetical in the US - it exists in Europe and elsewhere. Second, if it were here I'd want it not for the better "off-the-line" acceleration but for the added power and improved fuel economy that excess power tends to give a vehicle (like going from the LX450 to the LX470, a straight-6 to a V8, gave better mileage) and the commissurate increase in towing capacity. A V8 on the same car as a V6 will last longer because it doesn't have to work as hard, and it'll be smoother, probably quieter, and the added power can be used elsewhere.

BETO

Those of us who want a diesel don't need the quick acceleration off the line, we want/need the extra torque/power to pull a trailer or heavier load or more efficient vehicle all around, just like it was explained above.
The turbo lag can be fixed with a twin turbo, and I thought MB did this already, but I was wrong.

GLDriver

I thought towing capacity was same for Diesel vs Gas GL

mbslk350

I agree. Once you get going, it's fairly peppy. I think the 2-3 second (depending who you believe) 0-60 difference between the GL450 and the GL320 is mostly in the first second or two off the line. After that, they are not too far apart.

Big enough? Yes it is. I would have bought the 420 V8 if it was available, but the 320 is certainly fine.

DISCLAIMER: While there is definitely turbo lag on the CDI engine, the lag probably seems more pronounced to me than to many others. My other main driver is an SLK350 with a 0-60 time of just over 5 sec. It jumps off the line with a sudden burst of neck-snapping acceleration. Switching between the GL and the SLK can make the GL seem very leisurely from the line.

Danno4x4

I went from a 1985 300D Turbo Diesel to a the GL 320 CDI turbo diesel...

So to me, the GL seems like a hot rod. While there is some turbo lag... it really does not seem to be much at all...

By the way, the other day, I took myself and 6 other passengers to dinner about 20 miles from my house.... I ended up with 26.1 MPG for the trip...

Try doing that in ANY other vehicle that can also pull a 7500 Lb trailer.... Thats really the point of the diesel...

I actually prefer the way it drives over the gasoline model... If I want to accelerate in a hurry from say 45 MPH, if I am driving the diesel, I step on the accelerator and it happens NOW with no turbo lag...

If I am driving the gas model, I have to floor it, wait for the trans to downshift, and then wind out the engine until it gets to its peak power band.

j2w218

Sounds like my old '82 Turbo Wagon, ugly thing but, drove like a tank.
You should try giving some gas, while on the brake to help spool up the turbo faster. Of course, with these new fully electronically controlled throttles, and transmissions, I'm not sure if it will work like it did in the old days. And before you test, make sure you have enough room to make it safely, ;-)

Just my 2 cents.

GLDriver

Not really true for a 450. It is instantaneous ! In fact you won't know when it down shifted

lkchris

Not the case with Mercedes

Mercedes Enthusiast tested the ML420CDI last month and complained a lot about poor fuel economy.

This engine probably makes more sense in Europe due to the larger difference in gas vs diesel fuel price than exists in USA.

StevethePilot

Was it just a CDI or a Bluetec? An American market vehicle or the one they're driving in Europe? Manual or automagical? (Does MB even have a manual GL anywhere?) And know this; most folks in Europe think the GL is way too big, more vehicle than anyone needs and therefore too heavy so why bother it's a waste of resources anyways. Think about it - they drive more BMW Type 1's, Smarts and Minis than anything else. They're looking for upper 40's to low 50's for mileage! Wouldn't you if Diesel was $7/gal?

Nevada Jack

Physical size is a major factor in EU also. The roads are narrow and the parking spaces are smaller. This is one of the reasons they offer the SWB S Class where we only get the LWB. ML's probably are there best seller and I would imagine most are diesel.

Waiting-4-550

NJ, why are you on the GL diesel board. You're gone be a non-green GL550 guy.. Power please!!!

Nevada Jack

I gotta spread it around...and besides I was less than 10 days from delivery of one. That make me a tree hugger of some kind...although I wonder how many of these guys are going to add a chip and mileage be damned...LOL

Waiting-4-550

It's more fun being a gas-guzzler than a tree-hugger..

Nevada Jack

I don't know about that. I will miss the diesel...had them in the past and that was the what drove me to order the GL. Either one will be a great purchase with the only difference being the power curve. If they had not packaged the GL550 the way they did I would probably be waiting for a new E diesel wagon or have ordered another GL320 (or 420 if ever it came here.)

None of us can lose on this truck!