My 3IS is running great, as expected from a Lexus -- except for one minor problem. The outside air temperature readout on the dash is quite sluggish. When I started out today it read 82 degrees, which is about right in my garage. But after being in 105+ actual around 2 PM according to the local forecast, it only crept up to 85 after a 40-minute drive. Is that normal for this car or should I visit the dealer?

 

Another scenario I experienced is when the car is parked too long in the heat, the temp reading will be higher than then actual temp.
Last week, outside temp was around 82F and car readout is 93F. It came down after a few minutes of driving.
I don't know where the actual temp sensor is located, but it may read a cooler temp when driving due to airflow.

 

Local forecast is often incorrect, the forecast may be averaged-out for the whole zip code, there may be significant local variations. I would never use this to tell what the current local ambient temperature actually IS.

Yes, location of temperature sensor plays a role. I could see higher temperature readout when parked in winter ski resort - clearly some warmer pocket of air (from engine?) was trapped and skewed the readout. You need to drive it for a minute and it goes back to normal.

 

Coincidentally, there was a thread in Car Chat regarding this topic. You should give it a quick read as it may be of some interest:
https://www.clublexus.com/forums/car...-be-wrong.html

With regards to your car not reading it accurately, how long was it exposed to the 105+ heat? It's strange (to me) that it would be 15 degrees off. Is this the first time you're noticing it to be that off?

 

This happens in Miami a lot. I always see 100F+ when it's parked outside in the sun. Then it starts going down as I drive away.

 

Trust me, it was around 105 when I went out today. And this was backed up by the local TV stations, and my steadfast Echo device programmed for my zip code. After all, how could that be wrong?:

 

Thanks for the helpful responses to my initial post. It’s interesting that most of the errors reported were for readings higher than actual. In that my problem is for readings much lower than actual, I’ll probably ask the dealer about it the next time I go in for service.

 

Very easy to check - put a digital thermometer close to Lexus' thermometer and compare results.

 

Seriously?? I'm sure you'll make his day. And I already know his response.

 

I was hoping they’ll recognize the problem and replace the sensor to keep a good customer happy.

 

I'm 100% sure that your ambient air temp sensor is working properly. If you do go to the dealer and bring this up, they will tell you to pound sand.
There's a lot of factor that comes in to play when reading for accurate air temp. So unless you can come up with a case study to prove that your car reading is incorrect, then I believe you're wasting your time.

Most people with modern cars understand the difference in car reading and the weather app or even a wall mount thermometer. It all boils down to science.

 

I've never had a car that didn't read a little too high. Even more so, of course, after it's been sitting in the Sun.

 

Mine never seems to be too far from the forecasted weather, always seems to be within one or two degrees celsius

 

Good article about a car's ambient air readings:
http://www.popularmechanics.com/cars...eters-are-bad/