Mazda CX-50 2.5S Winter Time Road Trip Engine Oil Temp Observations
- Thread starter OneLonelyBurrito
- Start date
I have a 400k mile bmw M30 that was 160-170 oil temp for its entire non oil cooler equipped life.
I have had other engines that are 170-180 oil temp, and they lasted a long time, and weren’t sludge factories. In fact all that I can remember were 250k plus miles. They either got sold or taken out of service for chassis problems.
If OP confirms with Mazda this temp is normal I would not give it another thought.
I have had other engines that are 170-180 oil temp, and they lasted a long time, and weren’t sludge factories. In fact all that I can remember were 250k plus miles. They either got sold or taken out of service for chassis problems.
If OP confirms with Mazda this temp is normal I would not give it another thought.
Took the city/suburban route today commuting to and from the office so here are the oil temps from today. Starting oil temp was 5F and the ending oil temp when I got to the office was 158F after a little over an hour of driving and it took ~40 mins for the oil to get to 150F. On my way home, the oil temp when I was pulling into my driveway was 165F with the outside temp in the mid twenties.
Everything is working as designed as far as I can see, so I don't see a point in asking a dealership about it.
edyvw
$50 site donor 2025
IMO, that is a problem.
WHat is your coolant temperature? I was looking on at Rock Auto, Aisin thermostat for CX-50 is 190f.
The coolant temp once it warmed up was 170-180F, depending on if I was going down a hill or not. So the coolant temp is with in the normal range for the stock 180F thermostat. Running the heat sucks a lot of heat out of the coolant when its 10F outside. Then with the quantity of oil (almost 6qt of oil for a dry engine) that the N/A Skyactiv engine takes and no coolant to oil heat exchanger, the oil temps I'm seeing don't seem too far off from what I would anticipate.
edyvw
$50 site donor 2025
What are changes going downhill?
I mean, my BMW is also naturally aspirated with 7.3qt oil sump, manual (so less load) and oil temperature in city driving after 15-20min is around 220f at those low temperatures. No heat exchanger, but there is a radiator-type oil cooler with a thermostat at 230f. On the open road, I need 10 min, maybe at 10f temperature, to reach 220f cruising, maybe at 75mph.
It could be by design. IMO, if that is the case, they mitigated another issue with such a design. A larger oil sump could be for OCI's.
In today's day and age of CAFE everything, running higher temperatures is the most basic trick to be CAFE compliant and boost mog, not only bcs. EPA but also bcs. marketing.
I think culprit might be in thermostat opening too early.
Also, on Rock Auto thermostat is 190f. I wonder if you have some kind of "hot climate" package? Though that usually includes different equipment.
The thermostat probably can't react quick enough to prevent the initial coolant temp drop when starting to coast down hill, it always comes back up quickly though. So I doubt its faulty thermostat.
I see that, it definitely acts like a 180f thermostat, if you look at older Skyactiv engines with a true thermostat, they are rated for 180f.
It is most definitely a design decision by Mazda, but I have a feeling its not a direct design decision regarding temperature. Where as on your BMW, they could have made specific engine design decisions to better manage oil thermals.
Just spit balling, Mazda could have routed the oil passages further away from the coolant passages than in typical engine design and/or the oil passages are closer to the outside of engine block/head and more exposed to airflow through the engine bay. It could also be something like the oil sump sitting lower in comparison to the rest of the engine so its further away from the heat source.
edyvw
$50 site donor 2025
IDK, Aisin is a reputable company; heck, the OE thermostat might be Aisin. I would say it is a 190f thermostat, and you might have a failing thermostat. I was looking at part numbers; it is definitely different from CX-5, and it is cheap. I would start there.
Perhaps. BMW definitely has a more complex cooling system with an electric water pump, different mods of operation, etc. But, warming up is, warming up. My Toyota Sequoia warms up oil in a similar manner, too. BMW also has underbelly protection, so it retains heat. Does Mazda has?
I understand, but that is weird. Manufacturers are fighting for every drop of fuel. They introduce 0W8 oils just to be CAFE compliant. Bumping oil temperature is the easiest way to bump mpg. If so, well, who knows a reason.
I would start with the thermostat here. I think it is failing.
I was looking around at thermostats and I'm not convinced that the Aisin on Rockauto has the OE temp spec right. I'm thinking it may be the thermostat for the Turbo engine not the N/A engine. The coolant gets to temp reasonable quick when the heater isn't running and is acting similar to my previous car, a 2010 Chevy Malibu, in regards to coolant temp fluctuations while driving, so I doubt its the thermostat. When the thermostat failed on my Malibu, the coolant temp never went above ~160F even in the middle of summer before I got a chance to replace it.
The Skyactiv engine has about as basic of a cooling system as you can get, belt driven water pump, outlet side regular thermostat, although it does has a coolant to oil heat exchanger for the transmission fluid. The engine bay is completely closed up with grill shutters and underbody paneling.
Mazda is also known to make different engineering decision than most Manufacturers. So it wouldn't surprise me if they tried a bunch of different approaches to decrease internal engine friction and left the oil viscosity alone.
In my 2021 GMC Canyon with the 3.6L engine I monitored my oil and coolant temps on the way to work to day. 45 mile commute, 90% highway. It was 11-15F during the commute.
Through my Torque Pro app my coolant fluctuated between 172-178F (OEM 180F thermostat). The estimated Oil temp was 150-165F the whole trip. I'd like it warmer, but it is what it is.
My real concern is the transmission fluid temp. There is no bypass thermostat in these 8L45's so it gets cooled by the OEM cooler 100% of the time. My transmission fluid never exceeded 75F.
I'd say you are fine with those temps. But your post does make me want to look and see if I can use my Torque Pro app to see if my grill flaps are open closed, I'm sure there is something there.
Through my Torque Pro app my coolant fluctuated between 172-178F (OEM 180F thermostat). The estimated Oil temp was 150-165F the whole trip. I'd like it warmer, but it is what it is.
My real concern is the transmission fluid temp. There is no bypass thermostat in these 8L45's so it gets cooled by the OEM cooler 100% of the time. My transmission fluid never exceeded 75F.
I'd say you are fine with those temps. But your post does make me want to look and see if I can use my Torque Pro app to see if my grill flaps are open closed, I'm sure there is something there.
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