AirCon Power usage. - The Unofficial BMW M5 Messageboard (m5board.com)

IvanDias · 3rd October 2001, 22:51

I read the statement in a magazine that "a 3.6 with no air-con can surprise a 3.8 on the track".

Now before you 3.8 guys flame me, bear in mind that I know your car is better, and I want one!!!

So...
If this is true...
If the AC is belt driven and saps power even when not actually on...

My AirCon requires regassing and probably a new compressor. I live in England and would not use it remotely enough to justify the £300-700 quotes I get to fix it.

So can the mechanism be altered to effectively remove the drive to the system, and how much power would be restored for the all important business of going forwards ?

I would want the option to reconnect it if I ever sold it.

Thankyou,

Ivan.

Alan Archer · 4th October 2001, 14:23

A/C switched on may take 4-5hp but switched off it should produce no more drag than the viscous fan freewheeling.

This on it's own isn't enough to offset 315 vs 340 hp.

Who ever drives on the track with A/C on anyway ??!

I will offer this though, having owned four 5 series all with A/C

right from a 170hp 2.5, 184 2.8, 211 3.5 and my 340/3.8 i can feel the difference in throttle response immeadiatley when the A/C is on.

Indeed i hate driving in traffic with it on, because it dulls the throttle response greatly and i would say that you could get caught napping at the lights with your A/C on !!

momo5 · 4th October 2001, 20:06

Yeah I agree with Ivandias. The loss of horsepower by AC
is less than 5 hp.

If you seek higher performance, take compressor, evaporator and condenser out which gives you at least 10KG lighter M5. The one of the few weak points of M5 is its too much weight!!