Boulder GT3

I bought a 2006 E320 CDI 3 weeks ago and the first trip was to drive it from Colorado to Ft. Lauderdale. It’s a 25K Mile car, CPO and so on. I bought the diesel for the heck of it I guess. I didn’t want 4matic in Florida and the novelty of a CDI seemed interesting. A couple of impressions:

It reminds me of the “old” benz sedans before AMG was the hot ticket. Pretty stodgy but it doesn’t trolly track, is very quiet, not a handler but has a compliant suspension that works pretty well. In practice, even the 16” wheels have an advantage of not having to be so careful about curbing them. This is a basic driver for me so it’s fits the bill pretty well.

I didn’t buy a Bluetec because of the cost difference. I wasn’t sure I would be sold on the car and I can sell this one at a minimal loss if I don’t like it. I’m crazy for the MB 7 speed autos and that was the only real plus the Bluetec had for me. I’m not crazy about the more sophisticated emissions and the motor didn’t feel much smoother. The 7 speed is a big deal if it’s a keeper.

On the 2000 mile Colo-FLA trip I averaged 71MPH and 35.5MPG. The 71MPH includes gas stops and so on. I made no attempt to be thrifty. The tires weren’t highly inflated and I just drove normal. My calculations matched the computer. The car has such smooth roll on power in traffic it’s hard to not use it more at the expense of some fuel. It’s really fun squeezing from 70-85MPH. There seems to be little fuel penalty for going 80 vs. 65, The top ratios in the tranny are very well matched to how the turbo builds power.

The controls are simple and excellent. The navi is a a generation back but it found everything I wanted with minimal effort.

The car is clunkier than the gassers around town. Some lag but not bad unless you live for the throttle tip in of an E55. The 7sp E350 is more nimble around town but the CDI feels about the same as a 5speed E350 4Matic. I get about 30MPG in stop and go traffic. I get 25MPG in stoplight to stoplight BS. My wife’s Lexus RX350 gets 17 on the same stoplight cycle.

There is really nothing the car is doing that annoys me. I’ve got stone interior and that is a complete PITA to keep clean but other than that no complaints.

Too soon to tell if I would do it over. I would probably buy a E550 but I might miss the CDI novelty.

So far so good. Glad to be back in a Benz sedan after a couple of BMW’s.

MBNUT1

Good post. Do you find the diesel noise objectionable particularly when puttering around?

philfna

I had some of the same observations as you. I recently bought a E320 Bluetec (2007 so no adblue) mostly a V6 versus an I6. I recently drove to Minneapolis and back about 500 miles -- it did remind me also of older Benz's. The one thing I did when I got back was get a KD-Box -- the mileage has improved, throttle, and MPG. The car is quite snappy now. I am not sure if you want to invest the money (850 + 106 labor) in my case, but it has made this car really perform much more like a gasser in town, and really made it a monster on the highway.

The KD-Box installed in a jiffy, and was done by my dealer who said that it would not void the warranty. My biggest problem was finding diesel on my trip (well Winter Diesel).

I am so glad you enjoy your E320 CDI. The passing power on the highway is just incredible. Also the little bit of noise you hear gives me a bit of nostalgia....

BTW, how is the 5 speed tranny in your car? I find the 7 speed quite smoove, and am curious on your thoughts on that.

Thanks for sharing,
Phil

PS I think someone on here is selling a KD-Box for a lot less.

Boulder GT3

Not too annoying. I've got some diesel trucks so maybe that blunts my senses.

I do notice that it takes a long time for the car to come up to operating temp when it's <40 degrees. The heater will blow warm quickly but the motor rattles at a higher rate for maybe 20 minutes.

It still does not have comparable refinement to a gasser but it's close enough to weigh the trade offs.

It's got a bit of a diesel growl when you roll it on in the mid-range that I kind of like.

The big caveat is that I don't think there is a perfect car, boat, house, or whatever. It's all a series of trades and compromises.

Boulder GT3

The 7 speed in your car is better. Especially around town. It's cuts the lag, which isn't bad, down maybe 30% vs. the 5 speed.

I'd rather have the 7 speed on the highway too but the 5 speed works great. The engine has enough torque that in the 60-80MPH range I never really feel like I would downshift. The engine just builds boost and whoosh.

I'll find the black box if it doesn't screw up my CPO.

I meant the "old" Benz remark as a compliment but when I re-read my post it doesn't come off that way.

philfna

Get the KD-Box no ECU tuning it goes before the ECU, monitoring fuel, pressure, etc. Big difference my dealer is a Kleeman dealer, and it was an easy sell for me. I didn't believe the hype of improve MPG, torque, and HP but it turned out to be all true.

E320CDI must be quite similar in improvement to the 07 Bluetec.

MBNUT1

Those of old benz guys knew what you meant.

MBNUT1

Ok well this is something that I have wondered about. Does the mileage suffer significantly while coming up to temp. My commute to work is 11 miles the middle 8 of which is on the highway. I have wondered whether I would see that much improvement in mileage (over a gasser) due to the warm up time. I have averaged 22.7 over the last 5700 miles with my E3504matic but I have to work at it. I would have preferred a rear drive but I bought it off of a friend at work and he likes the 4matics.
My experience with the gas car is that I definitely preferred the refinement over the diesel. But right at the moment seems like a good time to reconsider the diesel given the current fuel prices.

philfna

Diesel is still 60 cents more here than premium. I drive 13 miles to work, and I get 33.8 miles (40 percent in town, and 60 percent hwy). I have Blizzaks on right now I imagine in Summer I'll get better with no snow on the ground.

PS it ws -11 here, and it started up just fine. No real appreciable mileage decrease over 10 degree weather.

Boulder GT3

The CDI seems a little less happy than a gas one before it's warm and like I said, it takes a bit longer to get warm. The MPG doesn't drop a lot when cold.

I don't think the the diesel is cheaper to run at current MOGAS vs. distillate price structures. Plus, the maintenance is more expensive. That said, it still uses less petroleum which is a good thing somewhere in the mix.

philfna

Did you fill up with Winter Diesel? Did you notice a drop in MPG? I have noticed about a 5 percent drop with Winter Diesel...

MBNUT1

Thanks for the feedback. I enjoy your factually based responses. I wasn't very clear in my thoughts behind my statement about reconsidering the diesel given current fuel prices. When overall fuel prices were high diesels were really bringing a premium which has been erased by the relative drop in gas vs diesel. My hunch has been that diesels will again become significantly more economical to run so the current environment might be an opportunity to buy one for a reasonable price (for example a dealer has several new 08's for 10K off). And as you said I like the idea of getting better fuel mileage for its own sake. I didn't understand your comment above about MOGAS vs. Distillate price structures. What do you see going forward of diesel vs gas prices?

MBNUT1

Here the diesel premium differential has dropped to around 30 cents or ~ 15% comparing your mileage and mine sure favors the diesel. 33.8 mpg for an e-Class vehicle just feels good. How is your mileage in stop and go? Seeing mine in the high teens just bugs me even though it isn't breaking the bank.

philfna

MBNUT1 I agree with your comments. Also, in 2010 when all non-ULSD goes away I think diesel will drop in price. Finally, I would get a non-UREA ADBlue vehicle. I got the 2007 since no AdBlue, and the V6 with 7G transmission.

MBNUT1

BTW my history with these cars dates back to 1960 starting my dad's '59 180 and '67 250SE, My '59 220SE, '62 220SE coupe, '89 190E 2.6 5 spd and current E3504matic

Polar Bear

It does take a long time to warm up, but the car has a "heater booster" (electric ceramic based heater) that will put warm air out in about two minutes - much faster than a gas car, as long as the electrical system's voltage is sufficient. If the voltage drops to what the car deems as unreasonable, it will turn the heater booster down/off. Otherwise, if you let the car idle for about 30 seconds to allow the oil pressure to rise and drive (easily of course on a cold engine) it will put out warm air VERY fast.

It is really a nice feature if your car is in cold weather and sits out overnight.

I have had one since 2/08 and love it. It is also a CDI (2005). I have put about 20k on it since then and love every chance I get to take it on a trip. I have averaged 41.6MPG on a 450+ mile trip, including rest stops and some in-town driving.

Polar Bear

Have you by chance calculated this by hand during a fill-up? The reason I ask is that the tuning boxes "lie" to the ECU in regards to the fuel being injected. This could potentially inflate the ECU's perceived MPG and this show you a different figure on the I/C.

The I/C calculates MPG based on how much fuel the ECU is supposedly injecting into the engine at any given time. I have discovered that mine is pretty accurate overall.

philfna

I have done the pump and mileage calculation. It seems fairly accurate. I suspect the cost here for the KD-box is a bit more of the bad stuff in the air. There is no such thing as a "free" lunch.

Boulder GT3

After cleaning the car up and reflecting on the first long road trip, the CDI is a keeper for a while.

I'm going to figure out the KD-Box. I've tuned some of my tow vehicles and always had good results as long as I didn't go over the top. In all cases, the internal dash MPG computer lied like crazy afterwards. I'm glad the MBenz still reads right.

One other thing I was thinking about on the trip and MPG. On I-75 in South Georgia and Northern Florida you can always catch a stream of cars running very fast. I slid in behind a group and ran a steady 85-110MPH for an hour. The mileage only dropped about .5MPG vs. 70MPH. I've never seen anything like that with a car. Usually, above 80MPH the mileage starts to fall off a cliff. The only thing I've seen similar is in some diesel yachts that are tuned to run a specific % of peak RPM's.

Another side note. One of the cars I was following was a black S55. Rare to see on the road. I followed him up to about 115 and he pulled away from me like I was chained to a fence.

Polar Bear

The CDI really is a great car, and a great engine so far. Excellent power and economy, and a blast to drive.

philfna

I would concur with Polar Bear the CDI is a great car. I got the 2007 Bluetec because Polar Bear found it sitting at a dealer in North Carolina. The diesel is just a blast to drive. I really enjoy it. My only concern with this car is in winter, and the traction issue. So far with Blizzak WS60's it has been just as good if not better than any front wheel car I have owned with all season tires on.

PackerFan

I too have an '06 CDI and have loved every moment of ownership. Great fuel mileage, good power, extremely comfortable and very reliable so far. MB did a great job with this car!

Boulder GT3

As I posted above, my first use of the 320 CDI was a 2200 mile road trip. I now have the first accurate reading of how it's doing in pure stoplight to stoplight city driving. I'll preface this by saying I'm pretty gentle on take offs but nobody waits. Spending time on race tracks with cars has made me "easy on the equipment". On the same 20 mile round trip drive taking my daughter to school that I averaged 11.5MPG in my Land Rover LR3 I'm getting 26.5MPG in the CDI. On that route I averaged 17.5MPG in a 2008 C300 that I used for a couple of days.

Around town you can tell but pretty quickly forget or don't care that it's a diesel. I'm never aware of any smell or fumes with the windows down and roof open. The subdued diesel rattle is present until about 10MPH but again, it's just different not really objectionable. I think the hot ticket to minimize "dieselness" would be the Bluetec with the 7 speed but sans the urea spritzer. Still, I'm very happy with the CDI and happier with it around town that I thought I would be.

Polar Bear

Yeah - I am not interested in the urea injection either. Although the E-Class W211 has never had urea, I highly expect the W212 will so it will be a 50-state car. I don't intend on ever purching a urea injection technology - I feel sure it is just a stepping stone to newer technology and will not be needed in the near future. That's one thing that prevents me from getting the ML320 diesel, since it went with urea injection.

Perhaps most drivers don't care, but I just don't like the idea of the technology in general - having to have that large tank, no spare, etc.

Boulder GT3

I'm not well educated on the 211. I knew the ML had injection and assumed the E did too.