Thermostats - 87 deg vs 90 deg?

[Al115]

Morning all,

I was changing the thermostat on my 1999 V70 T5 at the weekend, and noticed that the one I was taking out was marked "90 degrees" and the one I was putting in "87 degrees".

I know that some people have switched to an 87 degree thermostat deliberately as a modification - what effect does it have? Should I stick with the original 90 degrees or will the 87 have a positive effect?


Alastair

[nikgallagher]

I thought the 87 deg was the standard one, and the 90 deg one is for colder scandinavian climates.

[glock19]

Will 3 degrees make much difference ?

[Wobbly Dave]

Engine will run slightly cooler. It would be difficult to prove any performance gain.

[Kent Canary]

Will 3 degrees make much difference ?

I heard they had some chart success..

[nikgallagher]

Engine will run slightly cooler. It would be difficult to prove any performance gain.

Won't it run 3 deg warmer? Thought the temp rating was when the stat opened, allowing trapped engine water to circulate through the radiator?

[Gwaredd]

The engine will run at the same (operating)temp, but the stat will open 3 deg earlier meaning that the engine will be running cooler at start up & the heater will take longer to warm up, but at 3 deg you wont ever, ever know the difference. 3 deg is nothing in a car engine.

There will be no peformance gain at all because the thermostat is only a device that determines the teperature on which the trapped engine water is allowed to circulate back into the cold radiator,(as said by Nik) thus the operating temperature will remain exactly the same. The only way to make the engine run cooler is by fitting a bigger rad etc.

For this country, your best off with either stat IMO. Makes no difference, only to heater warm-up temp.

Gwaredd