[leoparker990]

There is a sign that when climbing a mountain turn off the a/c since it can overheat your car. Is this true or this would happened only to old/classic cars?

[stooker]

Originally Posted by leoparker990

There is a sign that when climbing a mountain turn off the a/c since it can overheat your car. Is this true or this would happened only to old/classic cars?

I think most modern cars in good working condition will do fine at normal operating speeds and load. I do see you are in the UAE, so if outdoor temps are in the 40 Celsius range, it might not be a bad idea though...

[a90]

Our cars (M) are way overpowered for normal street usage, the amount of power needed for the airconditioning is about 10hp max on a hot day.

From that perspective, a stock M5 will have 550hp 'left' on a hot day for driving through the mountains. Seems enough and should not lead to problems.

If you have an older car with old technology airconditioning (less efficient, uses more hp) it might lead to issues when you only have 100 / 120hp or so. In that case, yes take that into consideration on a hot day in the mountains.

[aerostar]

Originally Posted by a90

Our cars (M) are way overpowered for normal street usage, the amount of power needed for the airconditioning is about 10hp max on a hot day.

From that perspective, a stock M5 will have 550hp 'left' on a hot day for driving through the mountains. Seems enough and should not lead to problems.

If you have an older car with old technology airconditioning (less efficient, uses more hp) it might lead to issues when you only have 100 / 120hp or so. In that case, yes take that into consideration on a hot day in the mountains.

Not really about engine efficiency but heat soak, probably.

[jmg]

Keep in mind that the M3/4 has good amount of cooling for track conditions that is more than adequate for what you are describing.

Oops, thought I was in the M3 forum. Your S4 should be fine, just keep an eye on that temp since you are in the UA.

[Fundguy1]

It won't matter. You arent driving a poorly cooled monster motor muscle car or woefully underpowered 70s boat.

[Fast4d]

I remember doing that in an OLD seventies era toyota a few decades ago....

making probably 80hp. LOL.

[angelr]

I make a mountain climb every day that says "turn off ac for next 14 miles to avoid overheating"

As said, no issue if the car is modern and well maintained.

[JoosyJoos]

Your AC turns-off under heavy loads (WOT) anyway. It might be an issue if you were in an original 2002 BMW but not anything in the past three decades.

[leoparker990]

Originally Posted by angelr

I make a mountain climb every day that says "turn off ac for next 14 miles to avoid overheating"

As said, no issue if the car is modern and well maintained.

Yes, you are right, if your car is well maintained even it doesn't matter while your car is too old. It totally depends upon What condition of your car is? well maintained or not? And you are right dude, modern cars have no issue like that. thanks a lot

[GOLFFRR]

driving a BMW no, anything else you may want to play it safe and follow the signs recommendations

[m5james]

Just like low speed limits...this is mostly for older cars that were less efficient. Modern systems nowadays have better clutches that'll disconnect as needed and run a different refrigerant. I just rounded over 100k in my '10 X5M and topped of my A.C. after noticing it wasn't as cold as I'd prefer in CA's 90*+ temps vs WA's 60* averages...$34 later and it's ice cold

[Dackelone]

Normally I'd say leave the AC on. But... the OP lives in United Arab Emirates - so What is a HOT day? 40'C ? 50'C ???

I guess... I'd keep an eye on the oil temps... and IF you see more than 165'C oil temp... maybe turn off the AC.

Btw... during our summer Alpine drive's... I've never had a problem climbing the Alpine passes with the AC on.

Dack

Dack

[leoparker990]

Originally Posted by m5james

Just like low speed limits...this is mostly for older cars that were less efficient. Modern systems nowadays have better clutches that'll disconnect as needed and run a different refrigerant. I just rounded over 100k in my '10 X5M and topped of my A.C. after noticing it wasn't as cold as I'd prefer in CA's 90*+ temps vs WA's 60* averages...$34 later and it's ice cold

Yes, small 4-cylinder engine with an old, inefficient compressor, A/C might hurt performance, but in any modern car they have a good systems. But switching off the a/c reduces the extra load on the engine to run the a/c compressor.

[bd307]

Don't quote me on this, but I remember hearing a suggestion to turn the heater on in older cars during hill climb to keep it from heat soaking and on track to help cool off the systems.

Anyone has knowledge on this?

[Z K]

Originally Posted by bd307

Don't quote me on this, but I remember hearing a suggestion to turn the heater on in older cars during hill climb to keep it from heat soaking and on track to help cool off the systems.

Anyone has knowledge on this?

Turning on the heater helps cool the engine - you're venting the heat from the engine. It does actually work.

I've done this to keep my car from overheating on my engine swapped and turbocharged Nissan back in the 1990s which had various problems... the things I was willing to put up with to add horsepower back then... lol

But on a modern car, it is not necessary if your car is well maintained.

[MightyMouseTech]

Originally Posted by bd307

Don't quote me on this, but I remember hearing a suggestion to turn the heater on in older cars during hill climb to keep it from heat soaking and on track to help cool off the systems.

Anyone has knowledge on this?

I do this on track. Turn the heat on low, just out the dash vents, and aim them out the window.