Honda's problems on the Civic and Cr-V just keep growing. First oil dilution and now heating problems. This is a Canada article but I imagine cars in the northern US are experiencing some of the same:

Honda Civic and CR-V nightmare

 

I don't know about the oil dilution issues but I have had this problem with my 2020 Fit. I previously drove a 20XX Toyota Corolla that got so hot in any condition you could cook bacon on the vents. 0 degrees with driving snow, still hot after 20 minutes of driving on the highway. My Fit in not even 0-degree conditions but at freezing doesn't get hot, hot hot. It gets warm. I'm sure the car is warmed up but the heater doesn't get as hot as I want it. I've wondered if this is by design or a problem with the car.

 

Interesting .. "In general, Honda Canada spokesperson John Bordignon says the 1.5 L Turbo engine was, "designed with efficiency in mind" which means the engine does not produce the "high levels of excess heat" as quickly as less efficient engines."

I suppose technically, heat IS a waste product of combustion. A substantial one: I think if you hit 50% thermal efficiency that's considered great. (Someone correct me please ..). So I imagine that as engines get more efficient they will also produce less heat. I could see how a turbo engine running under low pressure, and held at low RPM by the CVT, wouldn't produce a ton of heat.

No mention of a thermostat here, which my mechanic brain would say would be the first thing to check ...

 

This isn't a Honda-exclusive issue. There are many other owners with small displacement vehicles who are dealing with no (or very little) heat in their cars.

On my own Fit, I've realized that the way to more heat is to simply drive it harder - my 6 speed manual makes that a breeze! After it's warmed up (no blue light on the dash), I make sure to keep the RPM's near 3k to ensure it's creating some heat and burning off any excess fuel/condensation in the engine.

Is it harder on the engine? sure it is, but this is the downside of designing an engine that's just too efficient (doesn't have to break a sweat with CVT and multiple speed transmissions).
I also make sure to change my engine oil far more frequently to reduce any excessive wear.

 

I don't understand what oil dilution has to do with lack of heat in the passenger cabin, and I don't understand why turbo and non-turbo cars are having the same problem. Can someone elucidate?

Thanks.

 

Elucidate... I like that word .

I think its the combination of automatic transmissions and efficiency-leaning ECU parameters. These engines dont develop and emit alot of waste heat compared to older engines, something about the burn characteristics is turning more of the energy of the combustion into volumetric change rather than thermal change, so you get more power and less waste heat.

Therefore you have the issue of oil dilution due to cold-weather driving and insufficient sealing around the pistons at low temperatures or whatever. The lack of waste heat also means that the coolant isnt heating up very quickly, and the heater core is being fed with relatively cool fluid all the time rather than hot. There's also the issue fo the thermostat not even opening at low temperatures, so you don't get any coolant flow when the engines cool enough, I think the radiator and heatercore are plumbed in series (can someone confirm this?). A low-temp thermostat might help but I think then the entire cooling system and engine management need to be reworked in accordance, and I think performance thermostats open at like, 30C rather than 50C, so it wouldn't work any different when it's cold enough.

Also if you don't have a manual, the automatic transmissions will try to favor lower RPMs for efficiency, hence not driving with Eco on, and they will tend to shift as early as possible. Personally, I tend to shift conservatively while my car is under temperature, but after 54C I start to shift around 4000 RPM just cause I like to, and will defeintely wind it out to red line at least once a week for fun. I don't drive the same on auto cars when I have to for work.

I know having higher intake air pressures from boost doesn't help, but maybe this issue occurs for all current Honda engines, boosted or not. I havn't seen as much of an issue on my little Fit, but I tend to change oil 2 times a year and not drive very much. I think if it's an issue for the NA engines, it will be made worse by the turbo, but it's an inherent problem with the engines being built too efficient and for warmer climates, and they apprarently overlooked people living in colder climates like us canucks.

 

The bottom line is Honda's in particular, do not create enough heat because the smaller vehicles are not heavy enough to create strain on the engine.
That stress creates heat, but also causes the vehicles to burn more fuel.

Take for example Volvo. They offer nothing but 4 cyl engines but you don't hear any owners with the same complaint.
Why's that? because the vehicles are substancially heavier and their weight combined with dual charging (turbo and super charging) creates more heat.
Proof of this is in the fuel economy numbers. Honda is always near the top for efficiency, while Volvo is near the bottom.

 

Clearly the solution is to simply drive it like it's track day...... all day ..... every day. If you're not smiling, you're doing it wrong.

But seriously, I've noticed in my 2018, if I'm accelerating slowly, the CVT is quite happy to keep the RPM below 1500. Great if your main focus is efficiency. Not so great if you're trying to heat up your engine in subzero temps. Sport mode does a good job keeping the revs higher without me having to resort to the paddle shifters. I wonder if it would be enough to make a noticeable difference in that climate though.

 

FWIW My 2020 Fit is driven in south central Alaska, and my heater is adequate for the winter here. It takes 15 minutes to feel warm when driving around in 0F weather, but after 25 minutes, it gets very warm, enough to want to turn it off for a minute to cool off. The harder it's driven, the faster it gets warm. In 20F weather or warmer it gets plenty hot within 10 minutes of driving, but this my subjective experience.