We were looking to replace our Ford Expedition; three kids grown so didn't need seating for 8 (for kids to take friends). Fuel economy was atrocious; combined city/highway was 11mpg without towing our tournament water ski boat (~3,500#+ on trailer). Normally I only tow the boat 12 miles each way, mainly on a freeway and level; we had stopped going to the Central Valley (California) long ago with the boat so no concern about towing it over two long climbs over hills.

I was looking for something smaller, more economical to drive, but with the ability to pull the boat the short distance to our site. I finally settled on the GLK250 because it was rated at 3,500# (I'm a little over that with gear, etc. but 12 miles on level ground is not an issue), and diesel so expecting it up to the task (MB has been making diesels for generations).

As everyone knows, it gets phenomenal fuel economy; I've driven multiple times from the SF bay area to So Cal at 80+ mph on I5 and gotten 36mpg. I've driven 70mph from our house to downtown SF (45 miles each way) and back and gotten 40mpg. But the greatest has been when pulling the boat to our pond; from start up to hitch up to the pond and launch, to pulling the boat out, driving home, parking the boat in the garage and unhitching, I generally get around 21-22mpg for the trip (double the Expedition when the Expedition isn't towing anything).

Add to that this twin turbo diesel has around 60ftlb of torque more than the Expedition, is 2,000# lighter, etc., and it's been a no-brainer.

Last week was the icing on the cake; I needed to take my boat to the central valley (about 90 miles each way, and over two 'hills" (a total around 1000ft elevation climb and back down the other side). Granted, I drove at 60mph (speed limit for all trailers in California is 55mph instead of 70+ like the rest of the country can do when pulling a trailer) with the exception of going 65mph up the longest of the two hills (around 1800rpm so just past torque peak). The trip out was from 250ft elevation, a total climb of about 1,000ft, and down to 175feet. The return was very strong headwinds (Altamont Pass for those that know the area).

Results:
Round Trip MPG: 24.2mpg
Out MPG: 26.2mpg
Return (headwinds): 22.4mpg

Up the biggest hill where I was going 65, it didn't even shift down from 7th all the way up.

So, I'll deal with some of the headaches, etc. That little SUV pulls much better than the Expedition ever did, The only advantage to the Expedition was a bigger slipstream (so fuel economy didn't drop much when pulling the boat). While the heft of the Expedition was good, the brakes in the Expedition were never very good even without the boat (could not get ABS to kick in on dry clean pavement). The GLK feels absolutely solid when pulling the boat and I frankly feel safer in it; it will stop faster than the expedition (trailer has disk brakes).

Anyway, I just wanted to give a data point to those that may be considering towing. I can't say anything about the GLK350 and towing, but all things being equal, I'll take the GLK250 any day!

Gordon (still happy now at 105k miles)

 

I just picked up one last week with 70K miles on it. It doesn't have a hitch, so I'm guessing it's never pulled anything. (Yet). So far, I'm loving it! Hoping I don't get ruined financially with BlueTEC repairs down the road... I replaced a Volvo XC90, so I, too, lost some towing capacity, and it's smaller (5 seats instead of 7) and a little lighter, but much quicker.

Do you know how to tell how much DEF is in the tank? Or do you have to wait for the 2 minute warning? Also, do you know if it matters who's DEF you use? I've seen prices between about $7 Tractor Supply, Wal*Mart) and $21+ (BMW,etc.) for 2.5 gallons.

BTW, are you using the trip computer's mileage, or are you calculating it? I clocked 40.2 MPG bringing it home 55 miles, mostly on the highway at 65-70 mph.

 

Using the trip computer. As for DEF level, I don't believe there is any way to see it on the dash. I have an Autel tester (about $400) and I can go in and see what the % is. But frankly, I'm thinking I'll just get a dowel and dip it in the tank (assuming it will go straight down to the bottom of the tank, figure out on the dowel where full will be, and check it that way. Much faster than hooking up the tester. Actually, I think it's kinda funny; if you run low on DEF, it will eventually warn you that you only have x number of starts left. I had it happen while on a 500 mile trip; luckily there was an auto parts place nearby and I filled it up. But I doubt if it says only 10 more starts I'm going to be able to drive 10 x 500 miles....

I've used Peak BlueDef 2.5 gal since the beginning. I was getting it at o'reilly auto parts, but I now see it at our Home Depot for about $2 less than o'reilly.

Yeah, if you don't go over 60-65mph, the MPG is crazy high....

 

Thanks for the response!
I thought of that, but, I've been cautioned by a couple of people not to let anything get into that tank or risk expensive repairs. Also, I looked in the fill cap and it didn't look like a straight shot.

Can I just fill it until it won't take any more?

Ha! Carefully planned...

 

Only problem with filling it until it won't take any more is those 2.5gal boxes are a pain to use; I once thought my tank was low enough it would take 5 gallons. It only took about 4, and then spilled all over the place before I could yank it out. I guess what I really need to do is to use a good funnel and take my time rather than using the fill nozzle that comes with the DEF fluid box.

 

Welcome to another Bluetec owner. You already have our sympathies

The DEF tank will hold a bit over 7 gallons, which should be enough to last through a typical oil change interval (OCI) of 10k miles. Has yours had the emissions recall work performed? If so, it may use DEF at a higher rate than originally designed, but should still last through an OCI.

The Peak stuff is fine, the AutoZone or O'Reilly brand stuff is fine as well. Heck, if you could fit the nozzle from truck stop DEF pumps that would also be fine. When the low DEF warning comes on, you can easily dump 2 of the 2.5 gallon jugs in there and call it a day. No need to lose sleep over it or try to measure it too accurately, or even fill it up more often proactively. Just let it tell you when it's low and then dump in 5 gallons.

 

That's what was strange in my case. I'm in the middle of a long road trip and I get the warning, so bought two of the 2.5gal PEAK DEF boxes. I was not able to get both in; overflowed. So whatever sensor that determines when to give me the warning must be out of whack.

 

If you have a code scanner, I'd see what code(s) if any are stored. Have you had your AdBlue tank innards replaced yet? I know mine is faulty (the heater) so it will cause CELs down the road when it gets cold; I'll deal with that under the extended warranty when it happens.

 

Thanks for the sympathy!

Yes, all the mods were done before I got it. I suspect the "A" service was also done, as it had just a little over 70K miles on it and had been on a MB dealer's lot for a month. The guy I bought it from told me it had been listed as CPO, but I'm not positive that is true, maybe, though; it's really clean.

I was thinking those bottles had some sort of shutoff in the nozzle. Not so, I guess. Can you tip a new full one up to put it in the tank? I've had many Diesels over the years, but never before one with DEF.

So, is the first warning the 10 starts warning? I think the manual referred to an earlier warning than that. ("Refill AdBlue At Workshop See Operator's Manual") Followed by "Refill AdBlue At Workshop No Start in .. km," or have the messages changed with the updates?

 

And here's the proverbial "religious" question: What do you guys use for oil? FCP has two kits, one meeting the 229.51 spec and the other the 229.52 spec. Does it matter? I've used Rotella T-6 in pretty much everything, (Ford 7.3, GM 6.5, GM 6.6, MB 350SDL, Kubota...) including lawn tractors and motorcycles for years, but it doesn't meet the spec.

 

I haven't had the innards replaced yet. I did get an error code a while ago (can't remember if it was the heater but probably was). Doesn't get cold here so haven't seen it in a while. But as you mentioned, it should be covered in the extended warranty (already had the work done, just waiting for the check....), so when it shows up again, I'll get them to replace it.

 

I use Mobil 1 ESP 0w30. It covers both MB specs for diesels.

 

No shut off on those bottles.... I don't recall the error, it was probably "Refill AdBlue...", but because I was in the middle of a road trip, I wasn't taking any chances. It was also odd because it didn't seem like a long time since I had added it (don't recall how many miles, but it hadn't been that many months). I didn't think it would need any so hadn't tried topping it off before the trip.

 

The first warning will be to service the AdBlue "refer to owner's manual..." etc. If you ignore this warning several times and/or drive several more hundred miles, the next warning is the "XX number of starts remaining" message. At that point, you can be certain the AdBlue/DEF is quite low. You should be able to dump 2 whole 2.5gal containers and still have a bit of room left. I believe with the updated computer settings post-AEM work, the rate of DEF usage has increased (along with DPF regen frequency). You should probably keep track of how many miles you run between having to add DEF, knowing that it used to be at least one full OCI of 10k miles.

Also, when filling the DEF tank, do your best to avoid any drips or spills. The urea fluid is pretty corrosive and spilling it on the top of the tank is asking for trouble. I keep an extra extendable tube from the last DEF bottle to use with the new bottle and attach it as an extender to the new tube. This helps ensure the tube is in the filler neck before I start turning the container over to refill.

It also helps to have the little breather valve at the top of fluid flow when the bottle is sideways, as it should not spill through there either. If any spills occur, wipe them immediately.

Speaking of oils: if your Bluetec is covered by the extended emissions warranty, we must use the proper MB spec oils. Don't give them one reason to deny warranty coverage should anything happen. Keep receipts of your parts purchases for maintenance and a good log book.

While I have nothing against Rotella T6 or any other synthetic HDEO, the Euro specs in general are a little stricter and tougher to achieve. The manufacturer approval/license is most important. The bottle must specifically list either MB 229.51 or 229.52 spec.

I prefer oils that also meet VW 507 spec, which is one of the toughest specs to achieve in terms of engine wear protection. You'll find that many oils meet more than one spec, such as the MB, VW and Porsche specs, or MB, BMW and VW specs. You'll also find that those oils will more than likely be 5w30, with some being 0w30.

I currently use M1 ESP 5w30 but I have used LiquiMoly, Pennzoil (Euro L, at Wal-mart), and I haven't yet had any oil-related issues. The Euro L is excellent oil for an excellent price.

 

Good info. I suspect when I overfilled during the trip it was because of the AdBlue service-refer to manual message rather than the start # countdown. So it may not take a full 5 gallons when that notice comes on, but will when it gets to the countdown.

There is a drain hole under the DEF tank; when I overfilled it, I poured a bunch of water down around the sides of the tank to flush it out.

Probably a good idea to refresh my memory on manual contents. I may find something new (feature) that I never noticed before....

 

I'll try to remember to hook my Altel up to see the % of DEF in the tank when the first message appears. Assuming it is a consistent level/setting across all vehicles, that would help determine how much will go in when the first message appears.

 

Since the thread raised some questions regarding DEF tank refilling, here's a suggestion. Buy a half gallon Mercedes DEF refill from your dealer. It has a valve built into it. After you drain it, cut the bottom off (or mostly off as I did). You now have a funnel you can use to fill your tank with aftermarket fluid that will shut off when you release it. Pour any leftovers back into your jug.

 

Since the thread raised some questions regarding DEF tank refilling, here's a suggestion. Buy a half gallon Mercedes DEF refill from your dealer. It has a valve built into it. After you drain it, cut the bottom off (or mostly off as I did). You now have a funnel you can use to fill your tank with aftermarket fluid that will shut off when you release it. Pour any leftovers back into your jug.

 

VW 507....You must not believe everything...
In our country, the VW 507 standard is nicknamed "catdog" neither cat neither dog. You probably don't know how many VW engines were killed? Catdog is a nightmare for R5 and V10 owners. Personally, I saw the mileage of the VW Turaeg V10 TDI 32,000 km - the engine after death. Catdog had no mercy. The VW Group has a number of disputes. Later, the group issued a report that the VW507 replaces all standards, but the old standard applies to V10 and R5 engines . There is not much talk about it today, but it was a big scandal in Europe at the time. Dieselgate, which was recently, was a much smaller scandal. Then he solved the VW concern in a Solomon way. I don't know how anymore ... in the end it looked like he paid people the engines, even though people broke them through their own fault .
Today, the advantage is that finding an oil that does not have the MB specification is a bigger problem than the one who has

 

I'm aware of VW's many shortcomings with a few of their TDI engines, particularly the "pumpe duse" ones from '04-'06. But their failures were primarily design-related, not oil-related. The VW505.01 spec was an attempt to band-aid the design problem but it didn't make much of a difference. Many TDIs from that era ended up with new camshafts and lifters, at a minimum. Similar story with R5 and V10 TDIs, which sheared oil down a grade and quickly depleted protective additives.

Again, mainly design problems which no oil can really save you from.

There are other reasons but suffice to say these engines were short-lived. In the US, we did not get the R5 TDI but we did get the V10 in the first-gen Touaregs.

VW was simply not investing enough in keeping up with diesel technology like other brands who had already gone common rail. In the US, there were no new TDIs from 2007 until 2010, when VW's first generation common rail 2.0L 16v engines came out. Those had their own problems, like intercooler icing and such.

The updated VW507 spec was intended for common rail diesels, which all of them are these days. I haven't yet read of catastrophic engine failure due to oil starvation or premature wear using VW507 and MB229.51/52 spec oils. In fact, having owned 4 TDIs previously, including a PD engined Bora, I have yet to experience a single engine failure due to the oil not performing as intended.

I would advise those of us with warranties intact to continue using the proper MB spec oils. As long as you change it regularly and keep it at the correct level, you should never have an oil-related failure.

 

It's exactly as you write. Here in the Czech Republic we have Ing. Jaroslav Černý, CSc, Institute of Petroleum Technology and Petrochemistry, Institute of Chemical Technology in Prague. He publishes various publications and performs chemical analyzes of fuels and oils. He published several publications from a workshop called Lubricant Myths because he found that 99% of people talk nonsense when talking about oils, including oil dealers and sellers. So there he explains how it really is. I will send you a link - the question is whether the translator will be able to translate it. Really great reading. In one work, he stated that the production of fully synthetic oil is relatively complex and expensive, so it is nonsense for fully synthetic oil to cost what it costs in retail, because the manufacturer would have to work instead of making money. This claim went so far as to place a bet stating that a truly fully synthetic oil would usually not be in stores because the price is very high. Finally, everyone saw an opportunity to shine and prove to be smarter than the greatest expert. Everyone went to the store to buy full synthetics and prove that the expert was wrong. When it was discovered that they had bought all the fully synthetic oils that could be purchased from us, they took them to the laboratory for examination. And the result: Not a single oil was fully synthetic !!! But what surprised the expert was the fact that the packaging of the world's leading oil producer contained 100% mineral oil !!! Here I send a link to the first 2 parts, if you can and want another, write.


WARNING: the links are in the Czech language. Use a translator
Lubricant myths, Myth one

Lubricant myths, Myth two

 

So, how does 229.51 differ from 229.52? Is one better, or is both better? The Pennzoil only lists 229.51 but the M1 lists both. Inquiring minds want to know...

If it doesn't matter then the Pennzoil is the obvious choice... (At least for a Scotsman!)

 

MB 299.51 is the original spec for MB common-rail diesels (or Bluetec) and will typically be found in 5w30 flavors. It is considered a low-SAPS oil which is formulated to protect your expensive emissions system, not just the engine internals.

MB 229.52 is the updated (upgraded, some say) spec that came out a couple years later. It places an emphasis on fuel economy, in addition to the emissions system protection mentioned above. These oils are typically higher quality base stock and are typically only found in 0w30 flavor.

Bluetec owners can use either oil without issue. 229.52 oils may be more difficult to find in local stores and may cost more, whereas 229.51 oils should be more easily available.

Note that some oils are labeled as 229.51 and 229.52 on the bottle. This indicates if an oil is approved for 229.52, which is a more stringent requirement, it also meets 229.51 requirements.

Again, oils that include a trifecta of diesel approvals (combination of MB, VW, Porsche, and BMW) are going to be your most reliable and safest choice.

 

And what about 229.61 ... or 229.71 ... or 229.72? This is the situation ... how to choose the best ... Ufff ...
What do you want the best for? Will you pour it on your head or fry the cutlets? Or to the engine? Of course I'm joking because you didn't write in which car, petrol or diesel and it's good to know how many cars the car will travel in a year. Whether they travel only in the city or even outside / if they leave the city 3 times a year it is not important /. "andreigbs" advised you as best he could, just forgot to write "to reduce engine life " ll write you more

 

I deleted the message due to a language barrier. The translator completely changed the meaning of the sentences. I only have to write with a retrospective check. So sorry