Car struggles to start (and sometimes can't) when colder than -20C/-4F

[Natureboy]

2008 RX350. Should I get a block heater, a battery heater or both? The coldest temperatures we get around here is about -25C/-13F.

I was told that all North American cars have block heaters installed at the factories, but I'm not sure that my car does, even though it was built in Canada.
If it does have a block heater and I just can't find it, would that warm the battery enough to be able to start the car?

Thanks!

[Bykfixer]

The battery numbers you see like 675 cca is "cold cranking amps". In extreme cold weather the oil is thicker too, which makes the work to crank the engine more difficult with a reduced cold cranking amps. Perhaps have your battery "load tested" to make sure the cca isn't below spec. But keeping the motor and battery warm will definitely help. Especially as the battery ages and cca is reduced. 

[aconis]

It may be not only battery issue if it keep cranking the motor but it won't fire up. 

[Natureboy]

On 10/29/2022 at 5:24 AM, Bykfixer said:

But keeping the motor and battery warm will definitely help.

Thanks. I will start by installing a block heater, since that's always a good idea to improve the lifespan of the engine parts.

If that is enough to start the engine, great.
If not, I'll load-test the battery.

I don't know about the US, but I'm finding it really difficult to find the right block heater in Canada... The Lexus dealerships don't even stock them anymore.