Hello, looking for a replacement for my old ML320 bluetec (which did great towing a 6k lb trailer @14-15mpg@65mph), and trying to find a similar experience for long roadtrips.
Also getting a 27ft airstream (6600lbs, 7600GVWR). Heavier, but more aerodynamic than we had before. Trying to decide between the GLE450 and the 450e and looking for feedback on realistic gas mileage between those two options, ideally looking for something comparable to the diesel. (14-15mpg while towing, 26mpg+ hwy normally). This will be wife's daily driver as well, so the plug-in hybrid option is a huge bonus. Would definitely need 240+ miles range minimum (and the 450e has a small gas tank). Any feedback from people towing midsize trailers (25-27ft) with either of these would be great!
Or..do we need to look at a GLS450 as well? those are bigger than I'd like (only two of us, so we don't need the extra seats).
Thanks

 

Wish I could help. Got my 6000# RV ready for my first AMG53 tow, new tires and all, then it was totaled by hail. Towed it @40 feet, parked to load it then all HAIL broke loose.
Former Bluetec, similar mpg.

 

Once the battery in the GLE 450e is depleted you are going to be stuck towing with that underpowered 4 cylinder that has significantly less torque and horsepower than the 6 cylinder 450. Not to mention 750 lbs of extra weight due to the battery. Personally, I would use that new trailer as an excuse to purchase a GLE 580.

 

Yes and no. Even when the battery is "depleted" the vehicle becomes a hybrid, but with a much bigger electric motor than normal hybrids, so more torque and horsepower for acceleration and better gas mileage. Agree the 750 lbs of extra weight cuts into towing capacity but the specs show it can still tow the Airstream. And the 450e is a dream as a daily driver.

 

The electric battery doesn't shut down when depleted and leave you with the 4cyl, it'll run hybrid mode at certain percentages / conditions, charge battery, run w/ electric as needed, run gas engine only when cruising. When plugged into the trailer connection, computer changes up engine management.

For OP, I would recommend looking around on turo (or similar) in your area for a 450e you could rent for a weekend or week, test out pulling your trailer in different conditions (full battery, low battery, etc).

 

If you are towing a trailer up a long incline, That battery is not going to help out much. Especially if you started the climb with the battery at its minimum level. Unfortunately, Mercedes does not allow for you to charge the battery with the engine during times of low battery use. (I could do this with my GLE 550e).

 

Did the engine management change up when the trailer controls were connected? I don't have direct experience with MB plug in and towing, but did w/ X5 plug in hybrid (small sub 20mi rated battery) and its battery level was never dropped to low levels. Its been a while so I dont remember how it was going up mountain passes etc.

 

I was assuming tthat while driving in hybrid mode, it just works like a prius? (keeps battery charged and uses it to supplement power), so in theory the battery doesn't run out? That's why I'm looking for some real world experience.
Basically trying to decide between this and the regular GLE450 ..but towing a trailer is a primary use case for us, so was hoping for more than the 10-11mpg I would expect from just the GLE450 while towing?

 

I think most PHEVs work like this where the car always maintains a reserve to be used as a "hybrid" to supplement the ICE.

 

I had a 21 BMW X5 45e (PHEV) - I towed a trailer and a smaller excavator with it. Before that I had an ML550 (W166). I wouldn't recommend a Plug In Hybrid if you tow routinely or long distances close to the max weight rating. I replaced that X5 PHEV with a 20 GLE450 and have been far happier with the experience.

My main observation was the weight of the hybrid battery pack (under the back seat of the X5) was very noticeable and the towing experience wasn’t great. The X5 had an air suspension and could level the rear end - but the rebound rate of the dampers and air springs made it feel overly weighted down without enough damping to avoid awkwardly large rebound over big heaves / bumps. It just felt very heavy in the rear end and made me less comfortable with the weight distribution over the front wheels.

That said, the low end torque of a hybrid made take offs easy and didn’t present any issues. Modern engines are overkill in most scenarios. I wouldn’t worry about going up hill with a hybrid - I had no issue. I usually worry about going down hill. However, coming down hill the hybrid regen worked to keep the load at speed without activating the service brakes. It was nice.

As for GLE vs GLS - I will say a longer wheelbase is better for larger trailers with big cross sections. Shorter wheelbase tow vehicles can feel like they’re getting pushed around a bit more on the highway by the trailer. Wheelbase is part of the reason crew cab long bed dually pickups feel so much more confident towing fifth wheels (plus the wider rear end) as opposed to a 3/4 ton short bed.

My main advice is this - determine how often you’ll be towing that Airstream and how far you’ll be going. If it’s two or three times a year, get whatever version makes you happy day to day. If you’re going on multi-week adventures for half the year…maybe get the non-hybrid and consider the longer wheelbase of the GLS. Either way, I’d recommend AIRMATIC for towing - both my ML550 and GLE450 had air suspension which I enjoyed while towing. Overall, I’ve been much happier towing with the regular GLE450 over the PHEV X5.

Also, make sure you actually have the tow package and verify your trailer brake pig-tail is in the footwell. I only use a wired brake controller with my GLE - never had an issue.

Edit: the other thing was on long tow days, I felt like I was just lugging around 700lbs of battery for no good reason. And overnight trips didn’t usually give me a chance to fully charge the battery. I did love the EV mode driving around town though. The X5 45e was around 13-17mpg while towing depending on the trailer which was better than my ML550 (9-12mpg), but not life changing. Normal long distance non-towing mileage was between 25-28mpg. Also, smaller tank did mean more frequent fuel stops - and I never got used to having a pressurized fuel tank (push button, wait for car to release the cap).

 

What kind of mileage did you get towing the trailer with the X5 PHEV?

 

Thanks. How big of a trailer were you towing with the 45e? We'd be towing a 7k lb airstream...I'd love to be able to get 13mpg+ with it. But I've been debating the GLE450 vs GLE450 vs GLS450 (we don't really need the extra space of the GLS though). What kind of mileage are you getting on the GLE450 mild hybrid now?

 

Its been a little while since but going across the flat middle america I recall averaging 16/17 on 89 octane w/ a trailer weight approx 4,500 lbs. No issues passing through Colorado on the interstate (I think MPG was in the lower teens), battery management handled everything, gave me electric boost when needed hybrid mode all other times. Considering the electric range on the x5 phev was 14 miles back then, I think the newer 450e should be fine.

If I were in the same position, I would lean 450e considering the plug in electric would serve us best 90% of the time.