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2021 Metris gas mileage is horrible

9K views 40 replies 19 participants last post by  bbcconst  
#1 ·
I now have 5,000 plus miles and have never been over15.5 MPG. Took it in and found nothing. Only asked if I use Premium which I have from the start. I carry at least 1,000 lbs of tools and never am on the highway. All my work is within 10 miles of my home. The shift points seem to hold on to long so some times I force it to go to a higher gear. Not happy since it was a reason i sold my 1 ton NV3500 for the 11MPH it gave me. I also seems to surge when you ease on the gas from a start or rolling away from a stop. I have to watch it or my tools wind up on the floor.
 
#2 ·
FWIW, I prefer driving in E mode with my typical 600# of gear. It comes off the line in second with no jolt, which I find hard to manage in C mode.

Having said that, you should be disappointed with 15 mpg.
 
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#26 ·
While I haven't bothered to confirm this with my van based on having confirmed when the engine controller goes closed loop with other engines the van engine controller is in closed loop mode shortly after engine start. With other engines this was when the cold engine high idle speed dropped to near normal (and with engines equipped with a secondary air injection system when I heard the air injection pump shut off). This RPM drop doesn't take but a few moments or so. My SOP is to wait after cold engine start until the idle speed drops before puling away.

Also, I have done a bit of data logging of my van's OBD2 data. Coolant temperature gets to normal operating temperature (approx 200F) in under 10 minutes. It takes me around 15 minutes to drive the 5+ miles from my place to my usual destinations which are with few exceptions within around a 5 mile radius of my place.

So the van engine gets up to temperature. And being 5+ miles and 15 minutes from home I have to drive the 5+ miles to get back home which has the engine running for another 15 minutes or so.

Sure oil temperature lags coolant temperature but given I drive the 5+ miles and 15 minutes to some destination and back home again the oil is up to temperature, too.

I do admit I occasionally (roughly every couple of weeks) take the van on a longer drive and on the freeway. Anywhere from 20 miles to nearly 70 miles (round trip and including the 10 miles I have to drive to get to the freeway then back home again after leaving the freeway). Not so much because of any concern the engine doesn't get warm enough from my day to day usage of the van but to sort of clear out any "cobwebs" from the engine. But the engine appears to be pretty clean running. It never manifests any signs of any benefit from the longer drives.

I would have to believe the OP given his usage of his van and with the 1000lbs of extra weight it is hauling the engine gets up to operating temperature.
 
#5 ·
I would suggest removing the 1000 pounds and then go for a freeway drive where you can keep the speed a steady 65 for 200 miles. If you do not get above 25 mpg, there is an issue with your van. I can easily get 30+ when traveling on a flat interstate even when hauling a full van of windsurfing gear, coolers, suitcases, etc.
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#6 ·
My experience is that the terrain and wind play major roles in gas mileage on interstates... that and being fully loaded. I've seen, in calm wind conditions, 29.2 mpg on a net downhill of rolling terrain and unloaded and 23.2 mpg on the same route in the reverse (net uphill) direction the same day. Over an 800 mi drive on interstates I've seen a low of 18.8 mpg (with a headwind and fully loaded averaging 66 mph in a mountainous route) and a high of 24.1 mpg (with a tailwind and fully loaded averaging 61 mph in essentially flat terrain). I've heard from other Metris owners that they experienced super low gas mileage (13-15 mpg) from "bad gas" (either below spec octane or impurities (water, etc.)). Anecdotally, "bad gas" seems to be an increasingly common thing this summer. Why? not sure.
 
#16 ·
My numbers match yours quite well. I can get it over 30 mpg only by driving 55 mph.
 
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#9 ·
I was quite disappointed and stressed with my first 1000 maybe 2500:miles' mpg; but it kept getting better. One of the things that really bites the mileage, is the trip computer for short trips and slow starts of the day. When my van starts, it blips 80 mpg and then 2.x idling ... forgot to close the door, my coffee in the house, my phone, oh maybe I need tool x ... but meanwhile the van is running, or I leave it warming up in the winter ... that's all time counted at 2.x that then needs to be recouped by driving efficiently.

I had a very consistent route / commute into the next town. Bit of local road, lots of interstate highway, more local roads. About 25 miles one way. My Dodge GC liked to display 25 mpg on the dial once I got on the interstate, while the Metris made me work for it and especially early on, I couldn't get that 25 mpg. Now after 10k. I can run errands in town, no highway and come back over 20. With a light foot.

The one postal worker I talked to one time said their mpgs were mid teens. And, it figures: always idling, always low speed. They drive stop and go from one house or mailbox to the next. That gives the van no time to go into overdrive and be fuel efficient. Gear 1 2 stop, 1 2 stop ... 1 2 stop ... repeat the whole day.

So. if you have a lot of short trip stop and go in the morning and evening, never really get on the highway, no coasting down, ... the mpg will be at the bottom of the ratings. Whereas if you do a long rural trip < 60 mph the mpgs will be towards 26 27 28 maybe more.

And it really is not about the weight. I have been quite well loaded up and gotten 27 28 mpg keeping up with fast traffic in the fast lane. But that's more the scenario of consistent speed in overdrive.

I think city traffic with a gas guzzling v6 v8 equipped van could net 8 - 12 mpg ... compared to a fuel efficient 4 cyl getting 15-20.
 
#13 ·
I used to always put mine in E, but quit bugging with it.
It really doesn't matter in the end whether E or C. ( did M the other day ... good way to ruin your gas mileage ).

The best " E " is in grey matter that controls the right foot.

Slower starts at the stop light.
And especially more coasting to a stop.

Drive like gas is $10 / gallon. Drive as if you have a fragile load that you don't want to break. Or that you're a limo, transporting the queen of England around town.

Perhaps easier to do in some states and cities than others, but not doing the typical stop light race like 70? 80? 90% of drivers out there, does wonders for fuel economy. There's four traffic lights right near where I live. Not coordinated, of course. Close proximity. You can see them all lined up ... and it is stunning to see people step on it without any consideration for what the next light is currently at only to have to stomp on the brakes. Not just young guys in sporty cars. People of all ages, gas guzzling SUVs, pickups, ... I just take my time a bit, try to read the lights and avoid having to stop 4 times. 😃
 
#15 ·
I used to always put mine in E, but quit bugging with it.
It really doesn't matter in the end whether E or C. ( did M the other day ... good way to ruin your gas mileage ).

The best " E " is in grey matter that controls the right foot.

Slower starts at the stop light.
And especially more coasting to a stop.

Drive like gas is $10 / gallon. Drive as if you have a fragile load that you don't want to break. Or that you're a limo, transporting the queen of England around town.

Perhaps easier to do in some states and cities than others, but not doing the typical stop light race like 70? 80? 90% of drivers out there, does wonders for fuel economy. There's four traffic lights right near where I live. Not coordinated, of course. Close proximity. You can see them all lined up ... and it is stunning to see people step on it without any consideration for what the next light is currently at only to have to stomp on the brakes. Not just young guys in sporty cars. People of all ages, gas guzzling SUVs, pickups, ... I just take my time a bit, try to read the lights and avoid having to stop 4 times. 😃
I find the accelerator pedal a bit too touchy in C mode. I get those smooth biug vehicle off the line starts in E
 
#14 ·
Yes, driving style matters. When we did a long East-West road trip, I averaged 22-24 mpg, with mostly city driving in SoCal traffic it drops to 15-18 mpg.

On avg. I get about 350 miles on a tank with mixed driving. Fill-ups are 16-17 gallons, so that works out to 21-22 mpg avg.
 
#18 ·
Back when I learned to drive it cost me ~ $1k in driver's education with, about 6 to 8 hours of theory / law / rules / ... and 8 hours of practical driving lessons. Followed by the 1hr driving exam, that consisted of 30 min of parking and maneuvering etc in a test environment and then a randomly drawn route ( like one of ten cards you pulled ) with a 30 min trip on everything from in town, urban and highway.

There certainly was a bit of focus on a relaxed and focused driving style. Plus with countless pedestrians, cyclists, scooters and motorcycles ... 😬

Then at the pump gasoline was already ~ $1/liter ( $3.50 / gallon ) ... three decades ago. When possible I tried to drive fuel efficiently, because that was a huge amount of money for me in terms of commuting 30 - 45 - 60 min, depending. At those prices, even with a small car ( sibling to a VW Golf ) filling up every week or every few days stung a fair bit.

So, anyhow, I try to be mindful of how I drive and sometimes play the mpg game.

It is healthier to drive relaxed too :)
 
#20 ·
Ah yes, drivers ed. We did it in high school (early 60's). Four of us went out for a couple of hours, three in the back and one took a turn up front with the instructor who had foot pedals for those hill starts (and emergency stops). We also learned from each other and had to take the criticism of our peers. When Canada went metric in '75, gas was 18cents/litre.
 
#24 ·
I have a 2021 Weekender with a pop top. After 10,000 miles I consistently get 23.5 on highway trips with lots of up and down mountains - loaded down and about 12.5 in the city with just the kids. The user's manual refers to C/S/E modes but mine was always in C (comfort) mode.

I think someone on this site (nobody at the dealership could) informed me that Mercedes switched to "C" mode only with the 9 seed transmissions on these models. Later on, someone at Peacevans commented that this may be a blessing in disguise because the battery charging algorithms were different in the different modes and people were inadvertently ending up with discharged auxiliary batteries when they forgot to switch to the correct charging mode.

I have come to really respect Mercedes design of this transmission and have accepted the poor city mileage. The car has plenty of pep off of the line and immediate downshifting when lane changing, etc. I would say it works flawlessly at any speed. The shift points are not noticeable and I use the paddle shifters for downshifting frequently on the long declines after mountain passes. Just my two cents!
 
#25 ·
Based on my experience with my 2020 126" cargo van using it pretty much within a 10 mile radius of home -- but just for an errand running vehicle and carrying no cargo/tools my van averages around 22mpg running 91 sometimes ethanol free and sometimes with 10% ethanol. (Van engine seems to not care which type of 91 I put in the tank.)

I think the 15.5mpg your van delivers is normal. The stop/start usage I assume you subject the van to and extra 1000lbs really hammers gas mileage.

Might mention my 2020 van has no auto engine stop/start feature.

All I can offer is be sure the van tires are properly inflated for the load you are carrying and try to mind how you drive. Often vehicles used in a business are driven rather hard as the driver is on the clock so to speak and wants to get from point A to B and on to C and so on ASAP. While the vehicle is driven in a law abiding manner (mostly) it is driven hard. As a consequence gas mileage suffers.

The van engine is pretty precisely fueled and monitored for same -- my experience over the years is this is typical of turbocharged (or supercharged) engines -- so if it was running "rich" the dash would be lit up like a Christmas tree.

A bit of a warning. Do not let the engine air filter go too long. You may have only driven the van 5K miles but working as hard as it appears to have been working means the engine is consuming besides lots more fuel lots more air.

I let the air filter go too long on 2 cars. (With one car I was distracted with caring for my elderly parents and just lost track of time. The second car was a (factory) supercharged car and I was at fault for not more carefully reading the service schedule and I let the filter go approx. 7K miles beyond the miles at which it should have been replaced.)

In both cases after installing a new air filter the engine ran better. Really underlined the importance of changing the filter on time.

So be proactive with the engine air filter servicing. Don't let it go too long and in fact I'd be inclined if I were you to change it early.
 
#27 ·
I don't really think it is the 1000 lb load, it is the startup and stop & go, probably a good number of stop lights and/or 4-way stops with some amount of expediency getting back up to speed.

I think I get around 15 - 16 around town with a heavy utility trailer loaded with 500-1000 lbs of cargo ... or like 1 yard of top soil.

My van easily sits around with an extra few hundred pounds of panels, and routine tools; and a square roof bar. Had to make a trip out towards the mountains today, to check on a property, do some quick maintenance, take some photos & measurements for some upcoming weatherization. Chucked a few extra things in the van, a few extra tool cases, a ladder or two, lawn mower, weed whacker, leaf blower, ... I did take some bags of mortar out, figured I didn't need to haul those. LOL.

Outside of rush hour, and I wasn't in a rush ... I know the route well. Rural highways with a few traffic lights and villages / towns, a couple steep hills to climb, ...

Just got back:

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It blipped 31.5 a couple times, slowing down mid way in the return, but I knew that wasn't going to be attainable. The computer goes something like 29.7 30.1 30.3 30.7 31.1 31.5 ( with the lit/100km conversion our vans do ) and this new best trip translates to 7.5 lit / 100 km. Which is about what my old 1.8 liter VW Polo / Golf / ... engine did back in the day.

Pretty solid.

Anyway, I hope there's some constant speed interstate or rural highway trips in OPs future, so he can experience some better mpg numbers. Go for a little drive into the country side on a Sunday morning :)

Also make sure your tire inflation is good all the way around, ... I know I need to check mine.
 
#28 ·
A couple short trip data points.

With 20.5 mpg on the dial; picked up about ~2500 lbs of cargo. 10min mixed trip ( local road, interstate on/off, lights, local road ) bit of up hill and getting up to interstate speed, a bit of coasting down and slowing for the interstate exit, 20 mpg, then half a mile up hill ... arrived with 18mpg

Super short trip. In town only. Rush hour. Traffic lights. Eco OFF. Trailer with a ditch witch on it. 2 miles. 15 min stop and go. Part up hill. Average speed 15mph. 11.5 mpg.

Probably not bad, all things considered, versus the typical pickup truck.

But yeah, rush hour, stop and go, not benefitting from getting up to speed and coasting down ... hard to get the mpg.