F1 cars don't go straight on the straights?

This has been bugging me for a while now. Here's a good video to demonstrate what I'm talking about: https://www.youtube.com/watch?v=0HjcAZC06Gc

Rosberg does it a little bit on the front straight, but it's really noticeable at 0:23 in that video. He comes out of the corner onto the curbs on the left side of the track, moves to the right about a full car width, then moves left again for the braking zone, touching the white line again at 0:29. To my untrained eye, that's just extra distance covered for no reason, but I've never driven a downforce car. Can anyone explain to me what's going on?

Maybe the sand gets whipped around if you get too close to the edge?

Maybe he is using the middle of the road so there is not enough room to be passed on the outside and the overtaking car would have to give up too much on corner entry to make the inside worthwhile unless really coming hard?

Maybe he just does that so he has some margin for error while he looks at his steering computer to make brake adjustments?

I just went and looked at one of my race videos... I do it too. So do the other cars. No one drives the very edge of the track on the straights. Huh.

Maybe he's driving at such a high level his reactions are based on what he is actually feeling in the car. The deviations you noted are pretty damn small in the scheme of things.

Giant Purple Snorklewacker wrote: Maybe the sand gets whipped around if you get too close to the edge? Maybe he is using the middle of the road so there is not enough room to be passed on the outside and the overtaking car would have to give up too much on corner entry to make the inside worthwhile unless really coming hard? Maybe he just does that so he has some margin for error while he looks at his steering computer to make brake adjustments? I just went and looked at one of my race videos... I do it too. So do the other cars. No one drives the very edge of the track on the straights. Huh.

I've been watching closely since last year, this happens on very nearly every track, every straight between two corners of the same orientation. At first I thought it was because of local track conditions (like sand or bumps), but it's too regular to be that. This was a qualifying lap so no need to worry about getting passed. It's more pronounced on short straights where I doubt they'd be making car adjustments. I sorta do it too, just because driving on the white line is uncomfortable, but I don't move over nearly as far as F1 drivers do. And it's every driver, if you watch during the race they'll all follow each other single-file, making each straight a little turn.

oldsaw wrote: Maybe he's driving at such a high level his reactions are based on what he is actually feeling in the car. The deviations you noted are pretty damn small in the scheme of things.

I watched an interesting video a few months ago about why F1 drivers don't take a direct diagonal route across long straights like Malaysia, where they cross from the right to left. It ends up that in a high-downforce car, there's so much tire scrub just in that little movement to point the car across the track that you want to maximize your corner exit speed by just letting the car go where it wants, and then moving across the track in the last 1/3rd of the straight. It's a bit counter-intuitive, but it made sense to me. The video went on to explain that Alonso was tracking further out on the sweeping left-hander at Monza for much the same reason -- he saved time by not fighting the car to hug the inside of the corner. I think it was a Racer's Edge video, I'll see if I can find it.

Unfortunately, this doesn't full explain the situation I described in the OP, at least not to my pea-brain, although I believe you're probably right.

In reply to steronz:

I guess it could be that the aero is more consistent in the middle of the road where the surface is the same on both side of the car for a couple feet.

I'd say that in the grand scheme of things is only a wee amount of distance but this is F1... there is a reason or you can bet it wouldn't be happening.

This sounds like a question for Steve Matchett!

Ah yes, found it:

https://www.youtube.com/watch?v=KSxWWWgQJkQ

eta: Ah! I hadn't considered the effect of the pavement on the aero. Very interesting.

If you want a far more obvious example of that, just look at the Indy race on Sunday. ALL the cars run to the middle of the track on the front and back straights just to move back to the wall to enter the corner. Their reason might have a different source though.

There has to be some sort of aerodynamic advantage. Running close to the wall likely causes more drag. Possibly from pressure wave reflection?

I am sure giving yourself a break from running inches from a wall at high speed certainly had stress relieve advantage also.

In reply to aircooled:

At Indy, with those downforce monsters they call indy cars, they are trying to break the draft promtply followed by holding the inside into turns 1 & 3

I think it's a little bit of all this; surface condition, aero, and the idea of letting the car run the way it's going to not scrub speed. If the telemetry didn't confirm it was the fastest way to go (and I assume it does), then as GPS said they would not drive that line.

The first guy around the track did it to avoid dust at the edge of the track, and to avoid countersteering for the crown of the pavement which will slow him down a tiny bit. Everyone else did it to stay in the tracks of the guy in front of them so they wouldn't pick up marbles.

And yeah it's also good for safety.

i bet they do it just to look cool, like in those Fast and Furious movies.