A propos of nothing in particular this Saturday morning, but I was just reading through a report on the World Solar Car challenge, which has been happening in Australia ( www.theregister.co.uk/2011/10/22/solar_car_tokai_advantages/ if you're interested.) The report contained this comment:

'Five per cent improvement in aerodynamics lead to two per cent less energy consumption. Five per cent is the difference between a clean car nose, and one which has flies on it, or other irregularities. So the car needs to be as smooth as possible at all times. Small things have great impact.'

So should I be paying more attention to having a clean car if I want maximum mpg?

'Five per cent improvement in aerodynamics lead to two per cent less energy consumption. Five per cent is the difference between a clean car nose, and one which has flies on it, or other irregularities. So the car needs to be as smooth as possible at all times. Small things have great impact.'

So should I be paying more attention to having a clean car if I want maximum mpg?[/size]

The solar-powered car in question has a CdA of 0.09, which is one-quarter of the Yeti's, and a frontal area of (at a guess from the photo) one-twenty-fifth of the Yeti's. Multiply those together and the solar car's total drag is about one per cent of the Yeti's. So if your flies were one hundred times the size of normal flies, you would get two per cent better fuel consumption by removing them.

Nothing new in this science; Supermarine were conducting the 'half pea test' in the late 1930's on the prototype Spitfire to ascertain the drag difference between half dome rivets or flush rivets. The half pea test involved sticking half peas all over the aircraft, then removing different areas to test the effect. From this trial they gained 20+mph and speeded up production by identifying were they could fit dome heads which were easier to fit without effecting drag.

The mornings trivia for you; might help come pub quiz time

However I don't think flies will have much effect on the engineering brick that is the Yeti

Regards,

TP

I learned a little about racing dinghy technology in my youth. Anti drag graphite paint on the hull was then the latest thing.

It has always been my experience that a clean and polished car runs more smoothly/quietly than a dirty one. I'm sure there is a real effect but have never seen any scientific research to quantify it.

To spend @ £20k on a possession and then watch it deteriorate and it's value decline seems odd to me.

Nothing new in this science; Supermarine were conducting the 'half pea test' in the late 1930's on the prototype Spitfire to ascertain the drag difference between half dome rivets or flush rivets. The half pea test involved sticking half peas all over the aircraft, then removing different areas to test the effect. From this trial they gained 20+mph and speeded up production by identifying were they could fit dome heads which were easier to fit without effecting drag.

The mornings trivia for you; might help come pub quiz time

However I don't think flies will have much effect on the engineering brick that is the Yeti

Regards,

TP

I read once that the commanding officer of a Spitfire squadron made his ground crews polish the wings of his aircraft with Beeswax...He claimed it made them 5mph faster.

When I flew commercially we often had enough dead insects on the leading edges of the aircraft to fill a small bucket.

Mr Boeing wasn't concerned at all though.:no:

Come on guys, leave your cars at home get the push bike out think of the savings/efficiency/health aspects -new sylph like figure would generate income on the high street new clothes etc - might also have negative health implications - heart probs etc!

think I'll stick with my dirty fly encrusted car with a smirk on my face as Sarko gets no road fund fee, less vat/litre than Cameron!

Whoopee!!!!

I read once that the commanding officer of a Spitfire squadron made his ground crews polish the wings of his aircraft with Beeswax...He claimed it made them 5mph faster.

When I flew commercially we often had enough dead insects on the leading edges of the aircraft to fill a small bucket.

Mr Boeing wasn't concerned at all though.:no:

Yes waxing and smoothing with filler was often practised particularly with the unarmed PR (Photo Reconnaissance) Spits that relied on height and speed for defence.

Been (very) lucky enough to fly in both a Spitfire (T.9) and the Lancaster back when I worked as an engine fitter; much nicer way to travel than a modern Boeing bus

Regards,

TP

To spend @ £20k on a possession and then watch it deteriorate and it's value decline seems odd to me.

If you've found a way prevent wear and tear and to stop your car from depreciating please let me know your secret!

If you've found a way prevent wear and tear and to stop your car from depreciating please let me know your secret!

You cannot, of course, stop a car from depreciating. But a neglected car will depreciate more.

I have seen cars with stained upholstery, smoked in and stinking. I'm sure you have seen cars with dull paint with permanent lacquer damage from bird lime and tree sap.Unattended to parking/supermarket car park damage, windows flecked with the remnants of stickers from pay and display and so on.

I'm lucky to enjoy keeping a car clean and as I like it. I do understand others don't.

I'm lucky to enjoy keeping a car clean and as I like it. I do understand others don't.

Normally I've done the bare minimum on previous cars to keep them presentable. Now I'm the butt of the neighbours jokes as I clean the car every weekend unless it's lashing down or I'm away. They are very aware I never did before!

I'm even doing under the bonnet & dressing the engine plastics as a matter of routine!

It had a pre-winter wax today & did seem to cut through the air a bit better than before!

I'm lucky to enjoy keeping a car clean and as I like it. I do understand others don't.

Want to keep mine clean, then?

I would have to wash mine every day in the winter to keep to that regime. If it is lucky it gets blasted with the pressure washer at Harry Tuffins on the way home from work occasionally, and certainly after a rally!

A good clean and decent wax will make sure the jetwash does a good job and the crud comes off easily.

A good clean and decent wax will make sure the jetwash does a good job and the crud comes off easily.

you going to volunteer then?