"...won't make a bee's dick of difference". Whew, I sure got a kick out of that! Terrific info, and I loved the humor.

Currently marathoning all these videos. These are answering questions I've had/ thought about for so long without any clue where to start looking for answers. My birthday is comming up, I think I know which book to buy for myself :D

Just a note on grill blockers. Don’t forget about the fans. If you have a mechanical fan that can’t be disconnected you will probably use more energy than you save spinning the fan against a restriction.

Finally someone who calls Coupé the way it should be pronounced.

5:37 Mercedes used completely enclosed hubcaps from 1968 until the mid-1980s without issue. My background is tier 1 brake system testing. You would need to subject the vehicle to absolutely extreme conditions, effectively hot laps for that open hubcap cooling to be a requirement

Practical and down to earth. Too much advice is spread around with sciency and hyping languange, but not here! Well done!

Another thing to mention would be to prioritise using the lightest materials possible while keeping everything safe of course if your going for fuel economy. Added weight equals more fuel use and though it wont be massive drop in economy it would make aerodynamic mods pretty pointless if better fuel consumption was the goal

Thumbs up for rear (roof) extension “spoilers” @7:25 for SUV-type vehicles. Reducing wake and possibly gaining a forward component aerodynamically should help with fuel consumption, especially in combination with an undertray w/ rear diffuser reducing lift over the top of the car...I’ve got to source some ABS sheeting...

I received your latest book today. Im glad to be able to support you.

This is interesting, because I'm currently planning on building a camper trailer for those overlanding trips and it's pretty much 95% DIY one. Haven't decided the shape yet, but this gives something to think about, because most driving will be on highways doing 80-100 km/h, so anything that'll help with fuel economy is worth doing I think (when deciding the shape of the trailer) 🤔

Now that I'm thinking about it, it seems weird that manufacturers aren't putting undertrays on themselves...

Great Info!

Great and well consumable content! Thanks. Would love to see your opinion on key differences when choosing right shape of roof cargo/box. What would work best? I own Subaru Outback 2016 and might need one for skis (so can be low profile and rather wider and longer to fit 185 cm skis). I know nothing about aerodynamics and not sure, what to buy to make the less impact possible. Thanks for any point, there is not much on the net about this topic

omg i have been lied to by all hollywood movies ; Thank you

I put a NASCAR style spoiler on my Monte Carlo. I was expecting lower mpg but went from 17 mpg combined to 21 mpg combined (through test of car’s odometer+ GAS PUMP. At next tank fill up I’ll no longer be paying attention to the odometer in that sense and I’m going to just use an app on my phone that is a bit more accurate in most cases

Thank you.

it can make sense to approach an aerodynamic form if you drive an open top car that has different hard top variants available. For example the Spoon S2000 hard top instead of one that is shaped like the standard roof.

Interesting about the air curtains. I am ordering an after market front wing for a mk1 MX5 that has those in the design. I thought they were to redirect some air towards the brakes to cool them down. But I guess it would do both.

some people use DUCT TAPE on their radiator openings

I’m curious about what material you used to make the rear spoiler. I’m interested in making one for my Golf R used for drag racing. I’d like to reduce wraparound/drag

Thank you, Julian, that's some great information, planning on an undertray and rear spoiler for my 04 Jeep Grand Cherokee. What are your thoughts about replacing the side-view mirrors with cameras?

Would rear fender flares work as well as whelk covers ? Or does fender flares even work at all?

My firebird seems to scoop it air up under the car with a plastic thing, creating a pressure to go up into the radiator.

What about pickup trucks that are higher off the ground. Anything there? My particular pickup has 15 inches of clearance to the floor pan (stock height).

Why is it that you want air separation at the rear of the car? Why wouldn't you want the air to smoothyl integrate at the rear? Might seem like a dumb question, but I really want to know

Thank you sir...you have given me great amount of info for my seminar presentation on Aerodynamics of race cars

Would love to see you do a reaction video to the aero modified tesla on the youtube channel 'boostedbois' - he literally made his own body shape to everything rear of the A-pillar and also taped up the gaps on everything infront of the A-pillar. All the mods improved his 1/4 time, however the question is whether it was due to aero or weight reduction...

Or increases exit flow of air from cooling systems

How can I reduce the drag of my Dodge Promaster City van?

👌👌👌

I don’t get why smooth hubcaps aren’t a thing in auto parts stores.

What about using separation edges on the front bumper, on the sides where it begins to curve. Have you tried this?

I am watching all your videos the last few weeks. They are great. Now I wool tuft tested my rear Window. Quite disturbed Flow in the middle. Then fitted 4 small Vortex Generators and after varying their angle 2 Times, I have attached Flow All the way down the rear Window. At the Moment I have no way to measure pressure. When I fit a spoiler lip I get more disturbed Flow again down in the middle of rear Window but still better than Stock. Is there a way to find out which Setup has lowest frag without measuring pressure on the Window?

@JulianEdgar how close would lowering the ride height be in the list of things that improve aerodynamics? Would it be in the top 10 and if so where would you rate it? I ask because my Tesla Model X has adjustable air suspension and I've contemplated replacing the static rear camber arms with adjustable camber arms to reduce the negative camber that accelerates inner tire wear while riding on the "Very Low" setting.

I was thinking of attaching some kind of plastic cover in front of the front wheels like many manufacturers nowadays do. What do you think Julian?

A bit confused as to why you want separation at the rear side of your car, can you please explain?

I ran into over heating issues at Road Atlanta in July. I installed an oil cooler and since then someone told me to duct it even a one inch lip around it. It sets in front of radiator corner so maybe the air build up on it will push air away not through it? I also installed a wind tunnel tested center hood louver that is supposed to help air passing through radiator escape in low pressure zone two inches behind radiator. Louver has big lip in front to deflect high pressure air up so air comes out of hood. I still have the small rear spoiler on my hatchback going up not down. Only because I think it helps car stability at high speed 140 mph depending on track. I had a skid plate under engine to smooth air flow but I removed it because I was scared of over heating engine and transmission. Any feedback thank you? Also, I have the best flat floor and rear diffuser I can come up with for now. I'll revisit that rear diffuser later.

so the small gap on the honda insight wheels is actually good!? i never thought about brake cooling holes! i was about to buy one of these completely flat discs for my wheels, would they make my brakes overheat?

Hi Julian. Would the addition of mud guards on a Prius Prime negatively impact aerodynamics/MPG very much? Is it worth adding them on for the protection they provide?

dangit, I took off the undertray of my car for a year lol!

How affective are winglets attached to the sides of a rear bumper? This advertisement attaches to the front bumper but I am going to attach them to the rear bumper near the rear back of the rear tires. smile.amazon.com/gp/product/B07T7ZZRGD/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

What about lowering the car? Would it help as less air goes under the car?

can someone explain me why the new, closed tires are all 4 the same now days? i mean, left and right side wheels turn in a different way, so why is one side pulling the air up while the other side is pulling the air down while driving? i realy didnt understand this 😕

Basically, electric cars are perfect at this

What are the practical gains possible depending on driving conditions? I live a simple life in the deep rural parts of the US midwest, drive locally on old fashioned two lane roads, and often never get over 45 MPH during daily driving. Combined with the fact that a lot of my driving is up and down grades in the hills, it doesn't seem like high efficiency automobiles get much better fuel economy on my route and driving style over my giant, flat faced full sized 1980's Ford cars and trucks, which certainly aren't aerodynamic. Aren't most aerodynamic gains realized in speeds over 45 MPH, in terms of fuel economy and acceleration? If I drive 25-30MPH in my small town, how much is the real loss of my wind kite bullnose 86 F250 or 79 Lincoln Mark V with their giant flat face grills? How much can I realize in terms of performance through modification? How much more efficient are newer designs really at lower speeds?

Hello, what is the effect of high or low pressure on the drag force of the car?

Hello! What could be the benefits / fuel savings if I implement those 5 upgrades on a 4 door sedan?? Mine it's a 06 SAAB 9-3...

Very informative content but the presentation is verbose. Subbed

Gladly most of these "tips" are illegal in Germany... Imagine everyday people would actually add lift creating rear spoilers to their hatches or block the cooling air of their motor. That's dangerous 🤦

Diesel? Low EGT? Son, there's a reason they have an EGT sensor and gasoline cars don't.

The problem is you are producing aerodynamic advice content with only superficial knowledge rather than first principals thinking , most of what you are explaining is your interpretation out of other peoples work and sadly interpretations are weak evidence and doesn't provide how to guide.