S Mode and mileage difference on/off

Haboob · 10-25-2014, 06:41 PM

The difference is probably negligible. I never drive the same way twice. Sometimes I punch it on the on-ramp, sometimes I don't, etc.

I could never do this study and have equal scenarios with SRM on and with SRM off.

Push370zzz · 10-27-2014, 10:29 AM

Quote:

Originally Posted by cjwsrt6

Why would I be joking, it was a question, that is what this forum is here for to ask questions and learn about something. Am I wrong?

Sorry, just thought it was a ridiculous question. It's like saying "is my car's top speed lower when both seat heaters are on?"

The definitive answer is that your gas mileage will be a little different, but the difference will be so little (in either direction) that it is essentially immeasurable. There are probably a dozen other things that would affect your gas mileage more than having S-mode on, such as A/C being full blast, passenger weight, cargo weight, etc...

damian_mb · 10-27-2014, 10:54 AM

lmao, people are funny when they say RPM drops below 2K RPM's in nuetral coming off hwy. I guess they need a video to PROVE them wrong. In S mode the RPMS stay higher coming off the hwy or while rolling and drops once you are completely stopped.

As far as screwing up your mpg, should be minimal. Also like someone else said, if you are worried about mpg, this isn't the car for you.

Try driving my WRX then talk to me about MPG. Drive it hard or grandma style, either way it gulps gas. Get on the gas, and watch the needle go down right before your eyes :P

Read T · 10-27-2014, 11:01 AM

I think the only way to test this would be to put the car on a dyno and establish a certain number of shifts and time of the shifts. There will be no way to test this in daily driving. There probably is a difference between on/off but it's so small it is probably difficult or impossible to measure. I do turn off SRM when the "E" light is on just in case.

With SRM on the engine will initially try to rev-match (not drop the RPM below 2000 maybe) if you are cruising at highway speed and then pop it into neutral to slow down for a stoplight if you aren't gearing down or pressing in the clutch.

Read T · 10-27-2014, 11:02 AM

Quote:

Originally Posted by damian_mb

Try driving my WRX then talk to me about MPG. Drive it hard or grandma style, either way it gulps gas. Get on the gas, and watch the needle go down right before your eyes :P

I was just blasting around the mountains with a friend who was driving his WRX. He was averaging low 20s (MPG) and I was getting about 15.

cooltoy · 10-27-2014, 11:08 AM

Quote:

Originally Posted by Push370zzz

is my car's top speed lower when both seat heaters are on?

Is it?

ghost_ix · 10-27-2014, 11:42 AM

Quote:

Originally Posted by Read T

I was just blasting around the mountains with a friend who was driving his WRX. He was averaging low 20s (MPG) and I was getting about 15.

my '13 WRX would consistently be in the low 20's, hard driving or not. My Z gets me 15-19 when pushing it

cooltoy · 10-27-2014, 11:55 AM

4 cylinders vs 6.

sp911 · 10-27-2014, 12:23 PM

Quote:

Originally Posted by cjwsrt6

Why would I be joking, it was a question, that is what this forum is here for to ask questions and learn about something. Am I wrong?

no. it is a good question. i also wondered that since when the car revs i would think it would be using more gas.

Chuck33079 · 10-27-2014, 12:24 PM

Quote:

Originally Posted by sp911

no. it is a good question. i also wondered that since when the car revs i would think it would be using more gas.

But you rev the car manually when you downshift with S mode off, so it's a tiny difference at best.

cooltoy · 10-27-2014, 12:26 PM

You have to rev match anyway when shifting down.

I would almost say you would save gas with S-mode, because the computer provides exact revs for matching, where as the human might over rev a touch, thus using more fuel.

cooltoy · 10-27-2014, 12:26 PM

Quote:

Originally Posted by Chuck33079

But you rev the car manually when you downshift with S mode off, so it's a tiny difference at best.

Beat me to it.

jpkirk · 10-27-2014, 01:20 PM

Quote:

Originally Posted by Read T

I was just blasting around the mountains with a friend who was driving his WRX. He was averaging low 20s (MPG) and I was getting about 15.

Quote:

Originally Posted by cooltoy

4 cylinders vs 6.

In all fairness, the Z's cup holds an extra 1.7 liters. Bigger cup, more fuel.

rapala · 10-27-2014, 02:27 PM

Quote:

Originally Posted by Chuck33079

But you rev the car manually when you downshift with S mode off, so it's a tiny difference at best.

Ok i got to ask,why do you rev the car manually when you downshift ?

cooltoy · 10-27-2014, 02:40 PM

WIKEPIDIA has a pretty good explanation.

Quote:

When a car with a manual transmission is in motion with the clutch engaged, there is a mechanical connection between the engine and wheels which keep them in sync with each other. When shifting however, depressing the clutch is required. This breaks the mechanical connection between the engine and wheels, and the engine speed is no longer linked to that of the wheels. When upshifting, this is usually not a problem, as the tendency of the engine to reduce speed itself without gas will slow it to loosely match the lower speed of the higher gear. However, when downshifting, the engine needs to speed up to come to speed with the wheels. If the accelerator is not "blipped" (or briefly and quickly pressed to speed up the disengaged engine), the engine will have to take power from the wheels and momentum of the car to come to speed, which is often accompanied by a sudden deceleration of the vehicle due to the power suddenly going to the engine, often described as a "lurch" or "jolt". This sudden external acceleration of the engine through the transmission also causes increased wear on the mechanics of the car. Therefore, a staple of advanced or professional manual-transmission driving is the "rev match", or "throttle blip", in which the driver quickly brings the engine up to speed with the wheels by use of the throttle. As downshifting is often necessary when accelerating out of a curve or other slow-down, advanced techniques such as the "heel-toe method" are often required, in which the toe of the right foot presses on the brake pedal, while the heel of the same foot blips the throttle.

Nissan's SynchroRev Match system makes such throttle blipping and advanced techniques by the driver unnecessary, and accomplishes engine rev-matching automatically.

10-27-2014, 11:01 AM	#19 (permalink)
Read T A True Z Fanatic Join Date: May 2012 Location: Raleigh, NC Posts: 1,046 Drives: 11 Nissan 370z BC 6M Rep Power: 18	I think the only way to test this would be to put the car on a dyno and establish a certain number of shifts and time of the shifts. There will be no way to test this in daily driving. There probably is a difference between on/off but it's so small it is probably difficult or impossible to measure. I do turn off SRM when the "E" light is on just in case. With SRM on the engine will initially try to rev-match (not drop the RPM below 2000 maybe) if you are cruising at highway speed and then pop it into neutral to slow down for a stoplight if you aren't gearing down or pressing in the clutch. __________________ 2011 Nissan 370z Black Cherry Sport Pkg - Daily Driver, , 1960 Morgan +4 fun car, 1986 BMW 325ES, 1998 M3 and 1996 Spec Miata - Race Cars SUPPORT TEAM WINSOME RACING - WRL, CHUMP, LEMONS

10-27-2014, 11:55 AM	#23 (permalink)
cooltoy Elite Member Join Date: Jun 2012 Location: Calgary Posts: 13,973 Drives: 14 PW 370Z S/T MT Rep Power: 243722	4 cylinders vs 6. jpkirk likes this. __________________ Member of kenchan's "photoshopped mods" and "proper offsets" gang.

10-27-2014, 12:26 PM	#26 (permalink)
cooltoy Elite Member Join Date: Jun 2012 Location: Calgary Posts: 13,973 Drives: 14 PW 370Z S/T MT Rep Power: 243722	You have to rev match anyway when shifting down. I would almost say you would save gas with S-mode, because the computer provides exact revs for matching, where as the human might over rev a touch, thus using more fuel. Chuck33079 likes this. __________________ Member of kenchan's "photoshopped mods" and "proper offsets" gang.

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10-25-2014, 06:41 PM	#16 (permalink)
Haboob A True Z Fanatic Join Date: Aug 2012 Location: Surface of the sun. Posts: 13,159 Drives: '18 GTI Autobahn DSG Rep Power: 1387	The difference is probably negligible. I never drive the same way twice. Sometimes I punch it on the on-ramp, sometimes I don't, etc. I could never do this study and have equal scenarios with SRM on and with SRM off.

10-27-2014, 10:54 AM	#18 (permalink)
damian_mb Base Member Join Date: Jul 2013 Location: MN Posts: 213 Drives: 12 370z / 13 WRX Rep Power: 12	lmao, people are funny when they say RPM drops below 2K RPM's in nuetral coming off hwy. I guess they need a video to PROVE them wrong. In S mode the RPMS stay higher coming off the hwy or while rolling and drops once you are completely stopped. As far as screwing up your mpg, should be minimal. Also like someone else said, if you are worried about mpg, this isn't the car for you. Try driving my WRX then talk to me about MPG. Drive it hard or grandma style, either way it gulps gas. Get on the gas, and watch the needle go down right before your eyes :P