Winter fuel mileage...I have concerns !

[Will721]

What do you mean by “these trucks”? You speak as though everyone is experiencing 30-40% mpg losses and there is something wrong with the design. I went from an average of 20 mpg to 17 mpg when temps are in the teens.

"These trucks" would be those that are experiencing it? The OP of this thread? Those in other threads? The fact there are multiple threads on multiple websites talking about it? Aka, not you.

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[Crazy Mary’s Husband]

"These trucks" would be those that are experiencing it? The OP of this thread? Those in other threads? The fact there are multiple threads on multiple websites talking about it? Aka, not you.

You are in the minority if you are dropping 35-40% and yet you are looking for something that is wrong with the design of the Tacoma. Maybe your thermostat is not closing on your transmission. Maybe you are too heavy on the pedal. There are a lot of maybes but if the design is flawed, ALL trucks would be affected.

 

[Yotota]

For all vehicles, there's a sweet spot of temperature range for fuel economy and it gets worse the father you are from that range. Hybrids are particularly affected by the cold, as are turbo engines. Ford Ecoboost turbo engines (both regular and hybrid) are even worse for mpg drop.

Personally, I write off fuel economy when I'm using any truck in very low temperatures. But that's rare in the PNW - I might see 15°F a few times per year, most of the winter I'll see low to mid 20s.

Idling the truck for warm-up or just keeping the heater running is one of the biggest issues in the winter. Then driving on snow covered roads at varying speeds, with steep climbs. I've had tanks as low as 12mpg after some snowboarding trips in my Taco. But I've also had plenty of fullsize trucks getting well under 10mpg in the coldest of winter. Even my V8 GX470 would dip down to 11-12mpg.

@MustardTiger - are you also factoring in the ~3.5% odometer error caused by your tire diameter? That would correct your 15.8L/100km to 15.27L/100km (15.41mpg).

 

[MustardTiger]

@Yotota my truck came with 265/70r18 tires, and I now have 285/70r17. The difference in diameter is negligible, like 0.3%. So an error in the speedometer doesn’t really exist. My tires are also SL (standard load), with Method rims…so added weight over factory tires and rims is also not significant. If I was running 10 ply tires, I wouldn’t be on here complaining about mpg lol…because that’d be a me problem based on my tire choice.

Also to note…my tires are at 32 psi.

Overall, I guess my reason for being bitter about mpg is due to the fact that with all the tech and engineering, small displacement engine, turbo, hybrid, grill shutters, direct injection, super thin oil, etc etc….my truck still sucks complete ass on fuel economy!! Under all conditions it should be noticeably better than an old 5.7L v8 Tundra with 300k running 5w30 pushing a considerably larger and heavier truck. But it’s not! And I even have the added headache and frustration of getting gas in the oil…and having to continually monitor the dipstick level…not fun. On my old Tundra, I’d change the oil just before winter, slam the hood and not bother checking it or changing it until spring. Never had to worry about it.

 

[Yotota]

@Yotota my truck came with 265/70r18 tires, and I now have 285/70r17. The difference in diameter is negligible, like 0.3%. So an error in the speedometer doesn’t really exist. My tires are also SL (standard load), with Method rims…so added weight over factory tires and rims is also not significant. If I was running 10 ply tires, I wouldn’t be on here complaining about mpg lol…because that’d be a me problem based on my tire choice.

Also to note…my tires are at 32 psi.

Overall, I guess my reason for being bitter about mpg is due to the fact that with all the tech and engineering, small displacement engine, turbo, hybrid, grill shutters, direct injection, super thin oil, etc etc….my truck still sucks complete ass on fuel economy!! Under all conditions it should be noticeably better than an old 5.7L v8 Tundra with 300k running 5w30 pushing a considerably larger and heavier truck. But it’s not! And I even have the added headache and frustration of getting gas in the oil…and having to continually monitor the dipstick level…not fun. On my old Tundra, I’d change the oil just before winter, slam the hood and not bother checking it or changing it until spring. Never had to worry about it.

Wow, I completely missed the fact that hybrid OR model trucks came with 265/70R18 tires (~32.6" diameter). I guess I had only looked at the regular trucks since day one. So yeah, the diameter difference is negligible.

What fuel economy did your Tundra get in the exact same temperature and driving conditions?

Does your Tacoma have any added weight, or aerodynamic drag?

 

[trailhunger]

If you drive a hybrid...the NIMH cell doesn't take over until it's up to temp. So own a warm garage (greater than or equal to ~50 deg) and you can get window sticker in the winter. All the rest of this is Sheldon-mathing & theory curves bleh bleh bleh.

Remote start, the 4 banger in the cold takes ~7 minutes to get to temp of course your MPGs will suffer in the winter.

 

[Will721]

You are in the minority if you are dropping 35-40% and yet you are looking for something that is wrong with the design of the Tacoma. Maybe your thermostat is not closing on your transmission. Maybe you are too heavy on the pedal. There are a lot of maybes but if the design is flawed, ALL trucks would be affected.

There are a large number of owners experiencing an issue. Not every owner is experiencing the issue. Not every owner will experience that issue. It could be there are a batch of trucks with bad trans thermostats. That's one possible issue but that itself would not directly cause the issue if not for the programming of the ecu. Which I'm not even saying is a design flaw either.


My observation was that Toyota seems to have very strict parameters and aggressive controls of the transmission. Again, that is not an issue in itself but a possible indirect cause of poor fuel economy in colder months. I also mentioned after market trans coolers and whether those owners who have installed them also experienced lower mpgs which could be an unforseen consequence to the install. The mention of the large number of owners who experience overheating in 4hi could also be related if the core issue is a bad batch of thermostats or other unknown causes.

 

[oxi]

How do electric fans figure into it?

My 25 Camry hybrid and my last 22 Corolla SE gas engine, they both dropped in mpg's during winter driving.

Reasons are simple: more idling to warm up, running heater motors, defrosting, colder tire temps, reformulated fuels. I can get over 500-mile range on my Camry during warm months and sometimes only 470 miles during winter filling the tank.

Tacoma I rarely drive because the Corolla and Camry with WS-90's handle the winter conditions just fine. Only major winter storm we just had, the Camry with WS-90's handled well, snow on the roads just missed my lower front clip, so no need to drive the Tacoma.

Cold temps play a huge role with colder tires, colder transmissions, colder engines, and running more fan motors.

 

[MustardTiger]

Did another 3 hour drive today, with a little tail wind helping me out…and averaged 15.4L/100km this time. All the same parameters as in original post. Tires are 32 psi. No additional unleaded weight other than maybe my tonneau cover?

My truck is parked in a heated garage, so it’s never really cold soaked, and I don’t idle it to warm up because it already is warm.

My dad has a 2022 dodge 1500 hemi, his avg mileage in these cold conditions is 13.1L/100km. And he’s running 10 ply 20 inch tires as well.

I’m not sure what the point of the Tacoma really is anymore. Certainly got me thinking that my ownership might be short lived…

 

[MustardTiger]

Wow, I completely missed the fact that hybrid OR model trucks came with 265/70R18 tires (~32.6" diameter). I guess I had only looked at the regular trucks since day one. So yeah, the diameter difference is negligible.

What fuel economy did your Tundra get in the exact same temperature and driving conditions?

Does your Tacoma have any added weight, or aerodynamic drag?

My Tundra was a crewmax limited, 4x4, 5.7, 275/60/20 8 ply K03 tires, 300k. In -25c conditions, it would get up to 16L/100km at its worst. Similar to my new Tacoma. It’s wild, man

 

[Yotota]

Did another 3 hour drive today, with a little tail wind helping me out…and averaged 15.4L/100km this time. All the same parameters as in original post. Tires are 32 psi. No additional unleaded weight other than maybe my tonneau cover?

My truck is parked in a heated garage, so it’s never really cold soaked, and I don’t idle it to warm up because it already is warm.

My dad has a 2022 dodge 1500 hemi, his avg mileage in these cold conditions is 13.1L/100km. And he’s running 10 ply 20 inch tires as well.

I’m not sure what the point of the Tacoma really is anymore. Certainly got me thinking that my ownership might be short lived…

My Tundra was a crewmax limited, 4x4, 5.7, 275/60/20 8 ply K03 tires, 300k. In -25c conditions, it would get up to 16L/100km at its worst. Similar to my new Tacoma. It’s wild, man

Crazy. Sounds like you're doing all that you can do, and your Taco isn't covered in wind-resistant stuff like roof/bed racks or boxes or anything. Have you tried running the air dam? Stock tires, right?

These Tacos were sold with nice EPA MPG numbers for advertising, but they are very optimistic for most owners since they are only really achievable under strictly defined parameters that include ambient temperature. Same for all other trucks.

I ran across these sites which show that the US fuel economy rule makers acknowledge the winter issue:
https://www.fueleconomy.gov/feg/coldweather.shtml
https://www.energy.gov/energysaver/fuel-economy-cold-weather

But turbo engines seem to deviate from mpg ratings greater than larger NA engines. Add larger tires without offsetting with lower gearing, along with more weight, and the turbo engine is "in the boost" more often while under load which quickly tanks the economy. This has been known for a long time among Ford Ecoboost owners (the largest group of turbo trucks on the market). Every EB Ford struggles to come close to the rated mpg numbers, even under perfect conditions.

 

[Yotota]

Personally, I can only hit the rated numbers when I run my stock wheels and tires, and drive like a grandma (or keep the truck in Eco mode), and not in below freezing temps. My truck only has minor bolt-on accessories like steps, tonneau, bed mat, and skid plates. No air dam because it's a TRD OR. When I run my larger C-rated Falken AT4Ws on Method wheels, my mpg takes a ~10% hit. And in the dead of winter, another ~10-15% hit for more idling and snow driving.

The hard part would be the question... What else would you buy right now? Used trucks - sure, there are options. But other new trucks?

GM trucks have been kinda crap for the last decade or more, Chrysler are even worse. Nissan is close to dead in the US. Ford has the Ranger or F150... The Ranger isn't bad, but all Ecoboost engines have issues that Ford likes to ignore (namely, cam phasers). And Ford still has some general QC issues like all brands. The biggest turnoff is the Ford dealership experience... Straight out of the 90s sleazy salesman tactics, dumb pricing, and stock issues for good trim levels.

If you want a fullsize, a Tundra is really it. Or an F150. For midsize, Taco or Ranger.

I wanted something new, that required minimal to no modding. I didn't want a fullsize due to downtown work parking. It was between a Ranger Raptor, or a Taco. And all the Ford negatives rules them out. So the only new truck I would buy is a Taco.

 

[oxi]

"I’m not sure what the point of the Tacoma really is anymore. Certainly got me thinking that my ownership might be short lived…"

Seriously? Is this a generational thing?

Tacoma is a mid-sized truck, which means more lifestyle than with work, but it can handle pulling a smaller trailer and load. It stands taller, has truck gearing (mine is 4.30 with the 6MT), and has ample running ground clearance numbers for good ol off-roading.

It's nice taking the wife on trips with my Tacoma, it rides higher than our daily drives, and we have the 5-foot bed to put gear and stuff we buy back there along the way.

I haul plenty of river rock, mulch and cow manure and anything oversize, so it has function, and that ground clearance with larger 265/70's R18 give us confidence in the country if we need to get somewhere, no matter the weather. Our daily rides cannot match what our Tacoma is capable of doing under some inclement weather situations.

The Tacoma is a great body on frame old school pickup, that is why it sells so well today. I am seeing more and more of them on the roads. What else would you drive?

Here are some of my images of past and current Tacoma's doing some work:

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