I have had an issue where the A/C compressor causes the engine to run about 500 RPM higher than usual. It happens only when the temperature is above 100, and only when the A/C is on.

I was wondering if those of you in the REALLY hot climates could report back this summer and let me know if this behavior is simply normal for the FEH under really hot conditions, or if I should bring my 2008 in for a check up?

Thanks.

 

I am in Vegas and have a new 08 FEH. When I am running home in the afternoon (110ish degrees) and the A/C is on the normal accleration RPM in the car is close to 2200-2400 RPMs (this is versus a 1700 RPM in the morning when it is only 80-85 degrees).

I would think that this is normal. I still can use the ECON on the A/C fine in running home and manage to get about 35ish MPGs when I am driving home in the summer (this is vs. the 41-43 MPG I get running to work).

Hope that helps.

 

Thanks, that checks. Evidently we have discovered something new about the FEH - the RPMs increase above 100 degrees. Now maybe someone can figure out why...

I take it you have a normal commute (20 min or more) and an FWD?

My commute is 10 minutes and I have an AWD. I don't see those kinds of MPG on my normal driving. I am getting around 30 - 31 on most tanks.

 

If you are able to go EV, then your HV battery is not overly warm. If the HVB temp gets over 95F, the FEH will force the ICE to run no matter if you have the A/C for the cabin selected or not. Whenever the compressor is on, the battery evaporator gets refrigerant. If the A/C for the cabin is selected, a valve opens to the cabin evaporator. If the battery temp is above about 85F, the A/C will run if the ICE is running, but it will still allow the ICE to shut off normally.

With the compressor running on my 2005, the RPM's are definitely higher, although I haven't noticed if it is even more so for ambient temps >100F. I have not been driving the FEH lately as my other car's A/C is vastly superior. Also the HV battery temp in the FEH is >95F even in the morning, meaning no EV and lousy mileage. Next time I'll try to see if I can detect such behavior, but I think you are probably OK.

 

Interesting. I was able to use EV mode at all times, so long as I turned off the A/C switch. Perhaps the 2008 is a bit different.

It is noteworthy that the 2009 has dropped the A/C of the battery pack.

 

I've been driving the past few days in 100+ temps, and my 2005 does not exhibit this behavior. RPM increase due to A/C is only 100 or so RPM. I can set cruise @ 45MPH and the RPM will be about 1500. My FE stinks, mostly because the ICE rarely turns off.

 

I'm starting to think that they changed the compressor type and/or CPU programming for the 2008 model.

 

I would agree with that. On the (so far) very hot afternoon days (say 110-112ish) when the ICE is running it is rarely under 2000 RPMs. In any sort of accleration (even very slight) it requires 2400ish RPMs. That said, I don't see much of a hit on FE, maybe a drop of 45 MPG into the 35 MPG range - still above the sticker.

That said, I think I have the ideal conditions to drive the Hybrid. I run 14 miles to work, all surface streets (45 mph), with timed lights - so I know what lights I will hit before I am anywhere near them.