Engine temperature effect on efficiency

[100SRV]

Hi,
the Rover V8 in my Bowler seems to run very cool - at motorway cruise of 60mph (with trailer) on part throttle the needle of the temperature gauge is just past the end of the white bit. It has an 84 degree C thermostat in and when the engine is warming up the needle reaches about half way along the gauge before dropping back as the 'stat opens.

Would running this cool have a negative effect on fuel economy?

cheers

100SRV

[stevieturbo]

You dont actually indicate what temperature you are running at.

But running cooler will have a negative impact on economy.

[100SRV]

Based on the temperature gauge needle position when the thermostat opens (at 84 degrees C) I'd guess it is running at around 60 to 70 degrees, I will put a thermocouple on it to get proper figures.

What is a good target operating temperature?

100SRV

[ringram]

IIRC Nascar and similar track V8's aim at 180F or around 84*C
LSx engines usually have a 160* thermostat and fans adjusted to target that.
Im sure different engines will be slightly different.

[stevieturbo]

ringram said:

IIRC Nascar and similar track V8's aim at 180F or around 84*C
LSx engines usually have a 160* thermostat and fans adjusted to target that.
Im sure different engines will be slightly different.

Cold stats are 160degF Richard.

Standard stats are closer to 98degC, which is nearer 200degF

[Pigeon]

Is the stat operating at the correct temperature? Stick it in a pan of water with a thermometer and cook it up...

[kremlingazette]

From my apprentice days, when you boil the stat up, make sure it is totally suspended in the water and not touching the container which will have a different temp, how good is that after 20+ years......

You may be aware of this forum but if your not, plenty help there too.

http://www.v8forum.co.uk/

[ringram]

stevieturbo said:

ringram said:

IIRC Nascar and similar track V8's aim at 180F or around 84*C
LSx engines usually have a 160* thermostat and fans adjusted to target that.
Im sure different engines will be slightly different.

Cold stats are 160degF Richard.

Standard stats are closer to 98degC, which is nearer 200degF

Yeah I meant to qualify as performance LSx builds hence why the fans need adjusting. Normal I think are around 195* as you say.

[lenientism]

I think engine needs optimum temperature in order to work properly. If that high temperature is reached after some period of work and cooling system can keep temperature not too exceed tolerable lever it will have best fuel consumption. Hence running at various temperature and speed will consume more fuel than that of running at temperature and speed relative constant.

But if the heat was for aggressive driving or some devices work improperly, it may produce overheat which can give the engine disadvantages.