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So in modern cars coasting in gear gets you better MPG, but how about our older cobras? Anyone test this?
Coasting in Neutral vs In gear MPG?
- Thread starter DarkRattle
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Did you honestly buy the car for mileage ?
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Considering I drive it the way I do to get 6 mpg. What do you think? It's an honest question though.
coasting in Neutral will NOT save u any gas. that is an old wives tale...... also engine braking is more efficient going down a hill.
fuel consumption is determined by how open the throttle body is, which is only determined by how depressed the gas pedal is. So there is no difference in you case.
when in neutral fuel has to be used to keep the engine spinning. modern engines are completely controlled by ECU to extract the power that we need based on our accelerator input.
when u come off the accelerator the ECU recognizes that there is no more power required and cuts off the fuel supply so when you are in neutral the engine will always be at idle RPM and will continue consuming fuel.
basically when u coast in neutral you will be burning more fuel than when you coast in a gear without any accelerator input.
fuel consumption is determined by how open the throttle body is, which is only determined by how depressed the gas pedal is. So there is no difference in you case.
when in neutral fuel has to be used to keep the engine spinning. modern engines are completely controlled by ECU to extract the power that we need based on our accelerator input.
when u come off the accelerator the ECU recognizes that there is no more power required and cuts off the fuel supply so when you are in neutral the engine will always be at idle RPM and will continue consuming fuel.
basically when u coast in neutral you will be burning more fuel than when you coast in a gear without any accelerator input.
Why would it consume more fuel? I would think you could coast further in neutral, given less drag, which would be where the fuel savings would come from.
When you're in gear the injectors shut off (if you have a wideband it'll peg lean) and the momentum of the car spins the engine. When your in neutral the injectors are on and running a 1.0 lambda to keep the engine from dying. It doesnt use much fuel but fuel is being used. Honestly doubt you'll see a difference either way. Coasting in 5th/6th (least drag) would be the most effective as long as you're reaching injector cut out.
Oh.. so now the injectors shut off. All kinds of good misinformation going around here lol
If you're getting that kind of mpg I'd be concerned about the health of the engine. My old set up with the BB/S and F1A would average 12-14mpg around town. And I wasn't nice to that set up. It would see full boost at least once every time I drove it.
It's not misinformation. It's called Coasting Fuel Shut Off (CFSO). Adjustments in the tune can me made for how fast or how slow it activates. And yes, it activates by shutting the injectors off when you're coasting with your foot off the gas. It doesn't happen immediately. On my current tune it takes a couple seconds. You can tell when it happens because the wideband reads full lean.
Does coasting in neutral help mpg? Maybe. But I doubt it's enough to make a noticeable difference.
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If you are only getting 6 mpg ,you seem to have issues.
My 01 swapped 91 fox, 18 in town , 28-33 on the hiway .
347 in my 84 , about the same , maybe a little less , in town , solid 28 on hiway .
I never had a Mustang , I tried to get good fuel mileage from.
Good luck
My 01 swapped 91 fox, 18 in town , 28-33 on the hiway .
347 in my 84 , about the same , maybe a little less , in town , solid 28 on hiway .
I never had a Mustang , I tried to get good fuel mileage from.
Good luck
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I full throttle basically stay second gear 6500 RPM for an hour straight canyoning almost everynight, normal driving I get 12-16 around town.
Like slo984 said, if you ever looked at the tune file for these cars you'd know that.
Lol thanks for the further explanation
Keep up the good (mis)information
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They do shut off.
It’s misinformation if you don’t explain the entire thing.. so yes, I believe it was misleading. You’re saying that the injectors shut off, in a discussion about gas mileage, when you know that it has no positive significant impact (one could argue it has a negative impact).
Spot on correct! Great post and explanation.
You could also just throw it in reverse, grenade the tranny, then save lots of fuel until repairs are complete. OP, get a Prius.
How is it misinformation? The reason the injectors shut off is to help MPG. I never said it was a big help.
You're the one that made it sound like we don't know what we're talking about in regards to the injectors shutting off. Your initial post makes it sound like we were wrong. Which I explained is not the case. So if you want to talk about misleading I could say your initial post is misleading.
How can having the injectors shut off have a negative impact? Going by your posts you didn't know it was happening.
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I don't find anything, actually proving one way or the other , except popular mechanics explanation with no data and regurgitation from that.
The gas-on rpm being lower than idle rpm argument seems lame at best.
I'd be interested in seeing an article with real data.
My Audi seems to get better gas mileage when I clutch into lights and don't get aggressive on the gas with shifts, but it has instantaneous MPG info and a moving average window where I can see the cumulative effects. I see no reason why the same would not be true for my mustang.
The gas-on rpm being lower than idle rpm argument seems lame at best.
I'd be interested in seeing an article with real data.
My Audi seems to get better gas mileage when I clutch into lights and don't get aggressive on the gas with shifts, but it has instantaneous MPG info and a moving average window where I can see the cumulative effects. I see no reason why the same would not be true for my mustang.
If you are coming to a stop, neutral is a better choice in my opinion. It puts less stress on the clutch.
However, engine braking with a full exhaust sounds amazing. It's an addicting sound.
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However, engine braking with a full exhaust sounds amazing. It's an addicting sound.
Sent from my [device_name] using the svtperformance.com mobile app
https://www.google.com/amp/www.popu...ric/amp5977/coasting-in-neutral-fuel-economy/
This article? There are two, this one has better info and addresses the inaccuracies of the factory MPG gauge. The other is pretty basic, neither has data sets though.
Like I higlighted though the difference is nominal and really hard to tell without lab conditions like on a dyno or something. Shifting a little different or hitting one extra traffic light in testing would skew the results. Would we a good Mythbuster type experiment driving on an oval for a whole tank.
6 of one, half dozen... neither way will show noticeable gains, more of an academic arguement. Just don't like when someone gets snarky, is wrong, then interchanges misinformation with misleading to try to save face (not you).
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