What's safer during the day - DRL or headlights ?

I'm surprised no one has mentioned the impact of having your running lights or low beams on during the day on the reaction time of the driver behind you. They have to detect the change in brightness or the rear lights and hit their brakes a short time after you do. Every millisecond counts. Don't ask me how I know. Twice in 6 months.

I want the contrast between normal and BRAKE! to be as vivid as possible.

Now in marginal light conditions, by all means use the low beams and the rear lights. But in bright light conditions (and especially on a red car) please don't.

And BTW, I added LED DRLs (toyota part number) to my car (v) after delivery and they are on whenever the car is running.

You do have to be careful because you can forget that you need to turn the low beams on as the DRLs show against a garage wall and can fool you. But the difference between DRLs and low beams becomes obvious once you are out on any unlighted street. A lighted street or parking garage can get you though because you can see just fine until you can't.

 

That has been one of my main disappointments with the Gen4. I think the brake lights are too small, and not bright enough. Especially in daylight hours. It would be nice if the brake lights extended the full width of the spoiler. (But I'm probably in the minority on that.)

In comparison, the brake lights and taillights on the Gen3 Prius are great! When those drivers apply their brakes, the long bright vertical LEDs immediately get my attention.

 

That is what the third center high-mount brake light is for. It is not part of the normal running light contingent, it is used only for braking.

The move from incandesent lamps to LEDs also provides 50-100 milliseconds of earlier warning.

 

Very true. If most cars have bright lights and one guy doesn't even have DRL's on, very hard to spot, especially with a quick glance.

 

Very true for me. Especially during periods of low light, I may miss seeing a black / dark gray / light gray car with no lights on. (Another reason I bought a *white* car.)

I almost broadsided a light gray/silver Gen2 with no lights, before dawn. I did the "quick glance", and even a 2nd glance and still didn't see him. I notice a LOT of Prii that don't use their lights... even when it's after dusk, or before dawn. What's wrong with those cheap people!!

 

I'm concerned about all the cars with front lights on but no rear lights, in fog or rain, approaching from behind they are invisible, seems about as smart as putting two new tires on the rear of the vehicle and used tires on the front, as, the front tires turn and do the most to stop, but why argue with insurance companies, just laugh and watch out for cars with no lights on the rear that are out of control on wet roads.

 

The Prius I almost hit had no lights on. None.

ANY lights would have helped, because it was still an hour before sun-up. Almost totally dark. That driver should have had full headlights & tail lights turned on.

I hope Prius drivers aren't purposely refusing to turn on their DRL lights... in some silly attempt to save money!

 

Canadian DRL are good in that regard: you can't shut them off. Still, as I mentioned, seems to be a lot of late model cars with BC plates and no DRL's lately.

 

This photo (courtesy of Automobile Magazine) is a very good view of the Gen4 tail lights and brake lights, during day time.

I may be in the minority, but I feel the brake lights are too small. I would like to see that wimpy high-mounted (third) brake light extend the full-width of the hatch lid. And the two other brake lights extend more vertically, the full-length of the "Z."

 

Another advantage to the lights-on thing.

I worry less about about other cars not having rear lights on because I always WX adjust my speed.
If YOU hit an idiot.....it's still your fault.
What can I say?
Life's not fair.
In some parts of the US we get torrential (sometimes called tropical) downpours.
Mountain folk call 'em 'toad stranglers' or 'gully washers.'
Sometimes you'll see truck drivers (and me) using flashers when this happens.
This will keep cell phone queens and GPS jocks from hitting ME, but I still have to be aware that some people have no idea why lights on when it's raining (and cruise control OFF!!!) is a good idea.

As far as tires are concerned, I buy four at a time, almost all the time.
If two of my tires wear out faster then I'm not rotating them often enough...and since big box stores rotate and balance for free AND give out free food samples this is a no brainer.
I don't run my tires down to 2/32", and since I don't drive in the city much I usually get 60-80,000 miles out of tires even changing them out at 3 or 4/32"
If I have to replace just one tire for road damage, then I'll still buy four the next time and keep the newer tire as a full size spare. Corolla rims are cheap.

One thing on the G4.
I'm sorry for all the mean things I've said about the Dodge Charger inspired rear lights.
Not personal, just a matter of taste, and I've tried to be more sensitive about them......especially in the G4 subsection.
One good thing about them is that when G4 drivers actually turn their lights ON, you can definitely SEE them.

 

"Toad stranglers." That's great.

I saw my first BLACK Gen4 a couple nights ago. He parked right near my house. It was a cloudy dark night... Looking at it from the rear, that Gen4 seemed to be invisible! All except for those long red "Z" tail lights.

 

Sometimes the sun angle affects your ability to detect the contrast. Either from your front or back, the sun can be so bright as to mask your ability to pick up the subtle color intensity change. I actually like the Charger style lights.

And of course in rain, snow, fog, mist etc put your low beams or at least the running lights on. I've been down to 25 on a winding 55MPH road coming out of the mountains this summer with everyone having blinkers on. Fortunately an area where the truckers knew how to drive. Not always the case.

 

Measure in 3 places across the width of the tire. The lowest depth is the one you use in comparing tread depth. You can find the original tread depth in the "specs" area for each tire at Tire Rack. Their site has videos showing how you can measure using a coin and what the recommended tread depths are and how they affect handling. Or you can buy a "professional" tread-depth gauge from most auto parts stores for around $3.

You could read their tests or I'll cheat and just give you the results. The difference between a new tire and one worn down to 2/32 (legal limit in many states) in a test on a water soaked surface was an almost doubling of stopping distance! 4/32 deep tires took about 50% longer to stop than new tires.

New - 195 feet

4/32 - 290 feet

2/32 - 378 feet

Even more startling to me is that on a 2/32 tire, in stopping tests in the wet from 70MPH the new tire would have stopped the car where the worn tire would only have slowed the car to 55MPH!!!! 4/32 would only have slowed the car to 45!!!!

They don't cite skidpad tests but the same issues that affect stopping distance would affect your staying on the road as you round the curve in the very wet. The tire needs the tread depth in order to evacuate the water beneath the tread and get the tire "rubber" into contact with the pavement. If it rides up on the water, it is like driving on ball bearings. I recall driving behind a car once and seeing it hit a puddle just as it came to a bridge and then going off like a pinball bouncing off the sides of the bridge. When I stopped, sure enough balding tires.

Depth does matter in the wet.

In the dry, depth is not nearly as important as long as the depth is consistent

 

As long as we're talking lights, one of my pet peeves: front turn signal lights that are tightly integrated in a cluster with the headlights. When the bright headlights are on it can be nigh impossible to discern if the turn signal's going, say someone oncoming at an intersection, maybe turning left, maybe going through.

Yup, good XMas stocking stuffers: tire depth gauge, tire pressure gauge. Lots of other good/cheap ideas: reflective vest, emergency flashlight with flasher, wheel chocks, and on and on.

 

The Prius must have that 'traditional center brake light '. It has been a federal requirement on all passenger cars since 1986.

 

Has anyone installed higher lumen LEDs in that fixture, or replaced it with an after market version that is brighter? I would like it noticeably brighter.