Rain repellent.

[john1000uk]

Presumably the application of a good quality rain repellant should reduce drag and therefore increase battery range. Has anyone come across any tests of this?

 

[Ian Key]

In theory a clean polished car will have a lower drag coefficient (I got a dictionary for Christmas ) than a dirty one.

Testing it out would mean a wind tunnel as in the real world there's too many variables which can skew the results. Rain, temperature, wind, road surface, etc. including the size of any vehicle you are following will all have an effect.

 

[Joningy]

Presumably the application of a good quality rain repellant should reduce drag and therefore increase battery range. Has anyone come across any tests of this?

I think as @Ian Key suggests, the word theory is key here, I like to keep my cars clean, whilst other's don't wash their cars for months, prime in my mind is keeping the car looking nice.

But obviously a clean car is definitely going to be more efficient at gliding or cutting through the air than a grubby dirty one, especially if you live in a shitty country area of countryside as we do.

Then you've got to weigh up the saving verses the cost of applying a rain guard, but in my experience spending money to save money doesn't always work out.

My AI assistant (possibly with a hangover from a heavy Christmas ) tells me the cost of a rain repellent is circa £30, plus any application cost, I don't think there will be a vastly measurable gain in either fuel efficiency or financial gain, almost certainly keeping the car clean will benefit efficiency in a small way more than a dirty one! .

 

[stevedee]

I had a chat with Duck.ai asking about racing cars. As far as dirty vs clean car, one of the comments was:-

• Drag Increase: Studies and real-world observations indicate that a dirty vehicle can experience increased drag by up to 5-10%, depending on the amount and nature of the debris.
• Performance Tests: In controlled conditions, racing teams have noted that cars perform better—often by several tenths of a second per lap—when maintained in a clean state compared to laps run with accumulated dirt.

Also, just as a reminder, carrying stuff in your car all the time, that you don't really need, or giving a roof-rack a free ride will have an impact on your cars efficiency; e.g. lower miles/kW

 

[Joningy]

I had a chat with Duck.ai asking about racing cars. As far as dirty vs clean car, one of the comments was:-

• Drag Increase: Studies and real-world observations indicate that a dirty vehicle can experience increased drag by up to 5-10%, depending on the amount and nature of the debris.
• Performance Tests: In controlled conditions, racing teams have noted that cars perform better—often by several tenths of a second per lap—when maintained in a clean state compared to laps run with accumulated dirt.

Also, just as a reminder, carrying stuff in your car all the time, that you don't really need, or giving a roof-rack a free ride will have an impact on your cars efficiency; e.g. lower miles/kW

Couldn't agree more @stevedee , I don't, (or can't) want to workout the exact savings of clean vs dirty, from mud picked up along roads, it's obvious to most of us, but totally agree with carrying additional weight, even a charge cable, and I wonder how much a dirty car wastes in both weight and drag? I've got a neighbour who travels everywhere with a tentbox on the roof, the drag on that must be very fuel wasteful

 

[stevedee]

I run my car dirty, full camo, as I like to creep up on people!

 

[Joningy]

I run my car dirty, full camo, as I like to creep up on people!

HaHaHa, so FTF are you doing discussing slick economy? Joking mate! just give me the stiff finger if I stand out from all you cuffy scrunts hiding in the hedgerows.

 

[salty]

I always like a clean car. And always joked a, clean car is faster, and runs better.
Seems now, it really, is/does.