Driving Lights and Engine Temperatures

Put a book infront of a fan, and your hand behind the book, theres no air flow behind the book.. same as lights and engine.

No quite Truckster.

When stationary . . . yes . . when moving , not really.

eg , stick your book out the window of a moving vehicle and you will get "some" air movement behind. It will be restricted , but some will be there. Same with lights. Yes , you can expect to have air restriction with lights , but unless completely covered by lights , it really shouldn't matter on modern 4wds.

Agree, but its the blocking affect - even with a book out the window, theres no direct air flow behind the book.. but there is air 1-2ft behind the book. Same as with your mirror - try it. Put your hand close to the mirror and move your hand backwards until you get the same airflow as infront of the mirror. There is quite a distance.

With the spotties, (depending on size) it will direct the air around the lights, which will be up onto the bonnet for most of the air...

if the radiator is designed for 75% airflow, and you put spotties there that allow 20% airflow, or 50% blockage it will make a difference.

The "NISSAN" badge from GQ's on the grill - around 17% airflow blockage just from that alone. (learnt that one from the Nissan club NSW driver training manual) And thats nowhere near as much area blockage as a pr of lights.

Throw a spanner in the works. the fan is an important part of the cooling system so if it is working effectivly wont it draw air in around the spotties rather than relying on air speed (undisrupted) to flow through the radiator.

Bruce I have a pair of XGT's on my Troopy, no problems at all.
The yota has never run hot.

rally cars have the spotties coz they have to have them or they would turf them. The light would cause airflow disruption but they have aftermarket radiators fans etc etc. Spotties will cause airflow disruption to his cruiser - the bigger the lights the more the disruption the question is enough to cause a problem? My experience says not

Hi Davoe, actually aerodynamics say he will not have any problems.
Using the rally car was just an extreme example of air flow.
Unless the driving lights are mounted against the radiator itself, there is no reason why the air will not simply flow around the lights, under them, over them and then through the radiator.
Cheers

Alan, I think the ones you see moulded into the bumper are mainly classed as fog lights (which need to be as low as possible to "look" under the fog).
My experiences are that I have 2 decent size Lightforce 240 Blitz's. I have sufferred from some "over-warming" issues (my Patrol has never actually overheated, temp gauge has just risen above half way on occasions before I installed a new radiator). On occasions I have moved the lights to the top of the bullbar (where they are at present). It does not appear to have made any difference to the antics of the temp gauge, but I'll leave them there anyway so that I can be sure the radiator is getting as much air as possible.
Cruiser owners never seem to have over-warming/heating problems, so I would say "go for it".
Good luck