Bonnet Guard

Would a bonnet guard improve fuel economy?

Would a bonnet guard have an effect on the Intercooler mounted above the engine?

Ive just seen alot recently and other than for appearance I wondered if there were any other benefits?

TJ

I gather we're talking about a perspex guard standing proud of the lip of the bonnet running one side of the vehicle to the other?

Confused! Why would a bonnet guard improve fuel economy?

and

Why would a bonnet guard have an effect on the Intercooler mounted above the engine?

Preventing stone chips is the only benefit I can see - waste of money IMHO.

It was something we were discussing at work.

The theory was that with the bonnet guard, that bit of plastic that sits on the lip of the bonnet, it would make the vehicle more aerodynamic. The other thought was that if the bonnet guard was pushing air up over the bonnet on to the windscreean and roof then could a top mounted intercooler become less effective. As most top mounted intercoolers sit below a bonnet scoop.

I was just curious to if this theory had merit.

TJ

No merit at all as it actually increases the frontal area of a vehicle and affects the airflow over a vehicle adversely. Most modern, and a lot of older 4X4's have some aerodynamic efficiency with their bonnet and front end design so all it will do is affect this.

Assassin wrote:

No merit at all as it actually increases the frontal area of a vehicle and affects the airflow over a vehicle adversely. Most modern, and a lot of older 4X4's have some aerodynamic efficiency with their bonnet and front end design so all it will do is affect this.

there goes that £5 bet.......

A bit late in on this one.... they are right you kow. The ONLY benefit is to protect the front edge of bonnet against stone chips, though they do tend to reduce the amount of bug blat on the screen. They look cool though.

A good alternative, if you want to protect the bonnet edge against chips is to use black 10 year vynil....

I find it easier to keep 1 litre of basecoat and some lacquer in, along with a little stopper, no chips in my vehicle, only on the plate with some fish where chips should be.