Temperature gauge question

As some of you know, I recently left my 2009 Corolla overnight to have a TPMS sensor replaced. As a result, I drove my wife’s 2016 Tucson to work. I noticed it took considerably longer for the temperature gauge to register than the Corolla’s does, I mean a couple of extra miles, a noticeable lag, and I couldn’t help wondering why? Are the two gauges just calibrated that differently? Different thermostats? More/less efficient cooling systems? Mom used to drive Fords and she referred to them as “cold natured.” I always wondered if there was any truth in it?

The Tucson probably has a larger capacity cooling system (it probably holds more coolant). The more coolant the system holds, the longer it’ll take to heat that coolant up to operating temp. My guess, anyway.


Hadn’t thought of that but some quick Googling shows 5.8 qt. for the Corolla vs. 7.9 for the Tucson so it appears you’re most likely correct. Thanks.

That is a difference of 5 pounds of coolant in a 250-pound engine, not going to make a difference.

If the engine does not reach operating temperature in 5 miles, the thermostat may be leaking. There is a rubber seal on the poppet that can fail.

It will take your 250 pound stove longer to heat 8 quarts than 6 also, no? Conceivably “a couple of miles”/minutes?

I tried to look at time differences to heat water by capacity. Found discussions on thermodynamics and gave up.

My whole commute is <10mi. each way. The Tucson reaches what appears to be its normal operating temperature (I rarely drive it but it seems to be normal for that vehicle) well within that distance–I didn’t pay enough attention to the odometer but probably in 4-5 miles. It just doesn’t behave the way I’m used to and I was curious.

did the weather get a lot colder than the last time you drove it? that could have something to do with it. just a thought.

I haven’t driven it in months. I normally glance at the temperature gauge periodically on principle but to be honest, the only reason I paid more attention this time is that I wanted to run the heater and I was waiting for the needle to move. No point in running cold heat, right?
Unless it’s really cold, the one in my Corolla moves noticeably in a mile or so; the one in the Tucson took considerably longer. There doesn’t seem to be anything wrong, it just behaves differently and I wondered why.

The heat always seemed to be available quicker in my wife’s old 2.7 liter 99 Camry than in my old 98 5.9 liter Ram. I just assumed it took a little more time for the larger motor and larger capacity of coolant to heat up. It wasn’t a huge difference. The heat would be warm in her car by the time you reached the state highway into town. It would be warm in my truck by the time you reached the city limits. Maybe a little less than 2 miles difference. :man_shrugging:

I would think a bigger radiator with more coolant would take a little longer to heat up, than a vehicle with a smaller radiator and less coolant. seems to be the case with my 2003 f-150 compared to any of my kids newer smaller vehicles they have had.

I’m not sure the size of the radiator makes much difference. It’s not really part of the equation until the thermostat opens, right? OTOH, there’s about a 1/2 gallon difference between the two cooling systems and if some of that extra is in the engine vs. in the radiator then maybe…
It might also depend on when the gauge starts registering. Does the needle sitting at minimum always mean stone cold or just not warm enough to matter?

That would be my understanding, the size of green radiator makes no difference. Coolant is only circulating in the block&heads until the thermostat opens. On a larger engine there is more metal to heat up too.

I don’t think so, never had problem with either the 09 Focus or the wife’s 12 Escape. I will say, a few years ago during the winter when the North East got hit with those dreadfully low temps (when I was driving it it was around 0 every day), the Focus would struggle to heat the coolant when driving 70+ on the highway down to work (I couldn’t run the heat higher than 1/3-1/2 or the coolant temp would drop from the middle to the quarter mark). I actually had to put some cardboard over the radiator for a few weeks, but that was the only time I remember the Focus having underheating issues.

For your issue, my guess is the larger engine just takes longer to heat and it’s not an issue.

Just to stir the “muddy waters” a bit to confuse the issue a bit more… I have two different cars I drive often. One, a 2019 Toyota Corolla SE (hatchback) with a 2L engine and automatic tranny. The other one is a 2020 Honda Fit with a 1.6L engine and tranny. I live .7 miles from the entrance of my sub-division (25 MPH speed limit) and the first stop light is about 1.5 miles away (the speed limit raised to 40 MPH after leaving the sub-division. The Toyota is putting out heat before I reach the entrance of my sub-division and the Honda doesn’t put out heat until I’ve driven about another half-mile or so (50 MPH after the stop light)…

The Toyota radiator holds 7.8 quarts of antifreeze. The Honda radiator holds just 4-quarts…

BTW: the A/C in the Toyota is a whole lot more efficient and easier to adjust…

To be fair, at the time, mom was talking about the 60’s and earlier Fords she knew. I’m sure (I hope, anyway!) current models are engineered differently. And surely there must be differences between makes.
As for a larger engine, the Corolla has a 1.8 liter naturally aspirated engine while the Tucson has a 1.6 liter turbo. Maybe something to do with a slightly smaller engine combined with a slightly larger cooling system capacity? I certainly don’t know.

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my honda turbo takes a long time to warm up.

certainly could be. The engine compartments are probably set up slightly different, might also be a minor factor too. Hopefully you had some heat by the time you got to work! It was really cold this morning in my neck of the woods in PA!!

Thanks. I had heat well before I got to work, just not quite as soon as I would’ve liked.

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