Optimum driving temperature (vehicle, not human)

[EmailAddress]

You have a gauge in the car. It probaby reads 60-130°c

It may be coolant, oil, transmission, or a made up value based on the general engine specs.

What do you consider 'operating temp', 'spirited driving', and 'overheating'?

Maybe you have intercoolers, or a turbo.

Is there too cold? Would you like your fan to kick in earlier. Do you cringe after a high speed run.

Interested to hear your setup.

[miniman]

Daily cars - gauge sits bang in the middle at 90 as most are damped to only move in extremis rather than reflect minor changes around 90.

TVR - not terribly interested what number it reads so long as it’s not much over 100 and the fans kick in and bring it back down.

[TheDrownedApe]

Honeslty I perked up when I thought i read "human, not vehicle" and came running to type 18.5 degrees.

Now I'm reading what I've typed and realise either way I'm over exposing myself.....that'll be the gin.

I will get my duvet

[Billy_Rosewood]

Oil temp.. I usually see upward of 70'c in most cars when warmed up and cruising.. Upwards of my 80-110'c for other driving.

Coolant usually bang on 90'c in most cars as that's around where most stats seem to open and fans come on..

TVRs may differ

[Mr E]

If the elise gets to 102 I listen for the fan coming on.

Billy_Rosewood said:

Coolant usually bang on 90'c in most cars as that's around where most stats seem to open and fans come on..

As noted above, artificially damped to avoid people getting twitchy.

[Mr Tidy]

I always wait for oil temperature in my BMW Z4M to get above 75 degrees before I give it any exercise - 10W60 oil is pretty thick at ambient temperatures!

I've no idea with my E90 330i daily because BMW didn't see fit to give it a temperature gauge.

[CoolHands]

85. But they seem to make modern cars run at 105 not for engine longevity but for improved emissions I believe

[Billy_Rosewood]

Mr E said:

As noted above, artificially damped to avoid people getting twitchy.

Not so much if reading from the ecu, surely?

The tvr would swing between 88-95'c but the old beemer would find a spot between 88-91'c and hold pretty solid there.? Never checked on the newer phev though.

[Pit Pony]

Mr E said:

As noted above, artificially damped to avoid people getting twitchy.

Having worked on the display requirements for a truck, I can tell you its worse than damping. Its an algorithm that puts it at 50, 60, 70, 80, 90, 100, 110 and engine fked your head gasket has gone in the red 120. 50 is between 45 and 55, 60 is 55 to 65, and so on.

[Cheese on Toast with Worcestershire Sauce]

Mr Tidy said:

I always wait for oil temperature in my BMW Z4M to get above 75 degrees before I give it any exercise - 10W60 oil is pretty thick at ambient temperatures!

I've no idea with my E90 330i daily because BMW didn't see fit to give it a temperature gauge.

You've got oil temp, no? Mine does.

[andy43]

Pit Pony said:

Mr E said:

As noted above, artificially damped to avoid people getting twitchy.

Having worked on the display requirements for a truck, I can tell you its worse than damping. Its an algorithm that puts it at 50, 60, 70, 80, 90, 100, 110 and engine fked your head gasket has gone in the red 120. 50 is between 45 and 55, 60 is 55 to 65, and so on.

Yeah the only ones I’ve felt give an accurate reading (or actually have temperature markings) have been TVRs. Sitting in traffic you could see the needles move - temp up, idle oil pressure down - the only cars I’ve seen that happen on.
And even then I remember accuracy problems as they’d fitted a sensor in a position that meant it was cooled down by airflow when moving.

[kambites]

On modern cars the "temperature gauge" is implemented as a ternery system which can indicate under-temperature, correct-temperature, or over-temperature rather than an analogue gauge - for example on our old Skoda a coolant temperature of anywhere between about 85 and 110 was displayed at exactly the same point in the centre of the dial, hit a point somewhere around 115 and it would immediately swing all the way to the red end of the dial.

Displayed as a dial because people like to see a dial, but implemented the same as a pair of warning lights because people don't like to see a dial which actually represents the real temperature.

My Lotus has a real (coolant) temperature gauge and in normal use, the temperature moves around a lot. If you watched the coolant temperature via the OBD on the Skoda it was the same.

Edited by kambites on Wednesday 9th April 07:25

[Pit Pony]

andy43 said:

Pit Pony said:

Mr E said:

As noted above, artificially damped to avoid people getting twitchy.

Having worked on the display requirements for a truck, I can tell you its worse than damping. Its an algorithm that puts it at 50, 60, 70, 80, 90, 100, 110 and engine fked your head gasket has gone in the red 120. 50 is between 45 and 55, 60 is 55 to 65, and so on.

Yeah the only ones I’ve felt give an accurate reading (or actually have temperature markings) have been TVRs. Sitting in traffic you could see the needles move - temp up, idle oil pressure down - the only cars I’ve seen that happen on.
And even then I remember accuracy problems as they’d fitted a sensor in a position that meant it was cooled down by airflow when moving.

It gets worse. My wife's mazda2 has a blue light when the coolant is cold which goes off after a minute and (I assume) a red light when you've overheated and the engine is toast.

[dontlookdown]

Pit Pony said:

It gets worse. My wife's mazda2 has a blue light when the coolant is cold which goes off after a minute and (I assume) a red light when you've overheated and the engine is toast.

This is not a new thing. I had a mid 70s VW Polo N (for nothing presumably, as that's the extras it had) back in the 80s when I was a penurious youth. It only had a single large red temp warning light in the space where the superior models had a gauge.

I remedied this by fitting a four dial dash from a Derby GT found in a local scrapyard, because everyone knows that a rev counter adds 5mph to the top speed, right?

[andy43]

dontlookdown said:

Pit Pony said:

It gets worse. My wife's mazda2 has a blue light when the coolant is cold which goes off after a minute and (I assume) a red light when you've overheated and the engine is toast.

This is not a new thing. I had a mid 70s VW Polo N (for nothing presumably, as that's the extras it had) back in the 80s when I was a penurious youth. It only had a single large red temp warning light in the space where the superior models had a gauge.

I remedied this by fitting a four dial dash from a Derby GT found in a local scrapyard, because everyone knows that a rev counter adds 5mph to the top speed, right?

Look in the manual for the red light and it probably says it’s a head gasket replacement indicator.
I added two extra gauges to my Corrado - it felt like a solid 50bhp extra with those fitted.

[J4CKO]

On my Fiesta ST its just electronic bars that are contrived to sit in the middle, I have a "Lufi Gauge" that displays all sorts of info, but mainly I use it to keep an eye on the water temp, mainly for on track, never been over 98, usually sits at 94 on the road.

[WPA]

Pit Pony said:

It gets worse. My wife's mazda2 has a blue light when the coolant is cold which goes off after a minute and (I assume) a red light when you've overheated and the engine is toast.

My Mazda CX-3 is the same dash, really stupid design as they could have easily fitted a gauge but instead fitted a big gear indicator screen, it has never made sense to me.

[GeniusOfLove]

The ND MX5, or at least the ND2 with the colour info screen thing in the dials, seems to have a real temp gauge and you can press a button to zoom in on the upper range for track/spirited use.

I saw it get over 110C driving hard in the Picos Europa in 40C temps going up big hills with the AC on. Turning the AC off dropped it down a lot!

[Megaflow]

CoolHands said:

85. But they seem to make modern cars run at 105 not for engine longevity but for improved emissions I believe

That. 85-90 C is the ideal temperature for coolant to run at, but there are emissions benefits to running hotter.

Oil, ideally somewhere around 100 C, up to 120 C is not a problem. Even 130 C for short periods.

Pit Pony said:

Mr E said:

As noted above, artificially damped to avoid people getting twitchy.

Having worked on the display requirements for a truck, I can tell you its worse than damping. Its an algorithm that puts it at 50, 60, 70, 80, 90, 100, 110 and engine fked your head gasket has gone in the red 120. 50 is between 45 and 55, 60 is 55 to 65, and so on.

Yep and on a Porsche, it is also connected to coolant level, if the coolant level drops it immediately goes to the max...

I found that out after the radiators hoses were done on my Cayman and after a few miles it cleared all the air out. I crapped myself!

Edited by Megaflow on Wednesday 9th April 09:28

[v9]

kambites said:

My Lotus has a real (coolant) temperature gauge and in normal use, the temperature moves around a lot. If you watched the coolant temperature via the OBD on the Skoda it was the same.

Edited by kambites on Wednesday 9th April 07:25

Yep, my bike has a digital temperature gauge and it runs anything between about 74 on a run in cool air up to 104 in traffic. Fan operates at 103 and brings it down to about 98 before switching off.
From memory I think the Stack display on my old Elise was similar.
Gauge in my car doesn’t have numbers but doesn’t seem to move much once up to temp.