Supra-holic

I like using some engine braking approaching a turn. I heel toe and rev match.

But I coast to a stop too like the post above, as for fuel mileage you might come out ahead or it may be a wash when coasting, you have to remember engine braking doesn't use fuel but robs energy.

What if two cars were at 100mph and one coast to a stop and one engine brakes to a stop then gets back on the gas to get to the other car? Which one uses less fuel per distance?

This isn't a post to encourage people to coast, driving safely is most important.

CapoArgentino

There's no benefit for going into neutral BUT some people are used to this after passing the 1/4 mile marker on a drag run, for no real reason. To me it's similar to the side-to-side rocking of the shift knob when shifting to neutral. No need to do it but some people are just used to doing it.

If you coast to a red light or stop sign in neutral all the time your brake pads will need changing earlier. It's always best to engine brake at any speed, all the time, specially in a sports car that is designed for this.

The other day on a steep downgrade of the 133 fwy I shifted into neutral at 80mph just to see how much speed would be maintained, just for fun. Of course there was NO traffic and I know how to rev match at any speed

rrounds

My (drag only)transmission in my old drag car would go to neutral as soon as I let off the gas.
If you look at all the in car video of drag cars(pro stock, pro gas ex.) you will see that they throw the transmission into neutral as soon as they cross the finish line.

ROD

flyingtoaster

I do it because my car is noisy. Cylinders don't get that hot unless you are racing.

The big problem I see at the track is people shutting off their engines after a run to save gas. I always leave my engine running for at least 5 minutes after a run and I usually never shut it off on a track night (I have lo jack). Engines get hotter after you shut them off. Compounding the problem, engines run hotter at the track and when you shut them off, there is zero oil flow and vacuum cooling. Any cooling problems resulting from throwing the engine into neutral seem incomparable.

SpitfireS

crank Posted on Jan 5 2011, 05:33 PM
Pretty cool, after part#1 I skipped to part#6 to see if they made it......

Btw.. IMO the Spitfire is like the S2000.
Form with function.

And.. when you coast (to a stop) in gear, when you reach idle rpm you can feel the engine picking up as the ECU does not allow you to coast/engine brake below idle rpm.
I've noticed this many times.

I've also noticed more engine braking with a lighter flywheel.
During busy highway commutes I rarely use the brakes, keep some distance and all I need is engine braking.

CapoArgentino

SLracer

I have to say I can say with 99.9% certainty that when you are driving on the road there is zero risk of damage by cruising in neutral. At the track racing due to high temps I guess something could be said about extra oil flow or whatnot but that is a mute point on the street. And for those of you saying you are not in control of your car in neutral I would say you would have to be a pretty awful driver to lose control because your in neutral. Sure if you need to accelerate again you need to rev match but I do it when I am definitely going to have to stop. The engine doesn't care how fast the car is moving, the engine is idling so despite your groundspeed no extra oil pressure is required. I have a 94 Saturn with over 250,000 miles that burns about a 1/2 quart per oil change and has exactly the same compression as it had stock (I checked, and this car hasn't been babied it has been autocrossed for 8 years as well as a DD). I coast in neutral regularly when going on off ramps, or to stop lights and have done it for the life of the car, so it mustn't have gotten the memo that its bad

SgtB

Full drag cars can't sink a lot of heat. Getting out of gear is to save the motor from wear. It's the same reason they shut down after inching forward in the waiting line. Some even have filled blocks and zero water passages in them.

I guess you could argue control issues on the street, but the motor will be a-ok.