S Mode and mileage difference on/off
 

Has anyone noticed a difference in mileage driving with your S mode on or off? I would think that with it off you would get a little better mileage but probably not much.. anyone run the numbers?

idk if you will notice a difference but if you are worried about mpg this might not be the best car for you lol

Nope. Not going to be something you can measure. Considering all S mode does is automate the rev-matching you do anyway, I'm not sure there would be any measurable difference.

I already own a z I was just wondering about it earlier and figured I'd ask. Thanks for the quick replies, maybe I'll check it next fill up and see

You can do a quick test on it.

1. Fill up your tank to max
2. Drive for 50 miles normally in S mode. Fill up and see how many gallons you used
3. Drive for 50 miles normally without S mode. Do the same step 2.

Personally I find using the S mode will decrease the mileage, but it really depends on if you do a manual rev-match when you downshift or not.

Shifts at 6000 -7000 rpm's tend to be bad mileage no matter how you slice it. ;)

S-mode keeps ur rpm above 2k even when ur in neutral. I can see a slight gpm drop.

The words, they make no sense.

Please elaborate, because I can recount numerous times that my car has dipped below 2K. My daily cruise to work, when I pop it into neutral coming off on an off-ramp, sitting in traffic, etc. I never turn synchro-rev off because I am a pansy who can't heal-toe.

The only way I could see it using less fuel is if you are a master of the manual transmission and can get every downshift perfect. I'm sure there are people out there who can do it. Depending on the type of person reviewing the car, they either loved s-rev, or hated it, because they were better at it than the ECU.

To rev that quickly in all situations, it must have to dump quite a bit of fuel into the cylinders.

Well thats the beauty of S-Mode, you can turn it off.

What?

No, SRM does not keep your car from dipping below 2,000 RPM.

You have to be joking right, how would rev matching affect gas mileage in any sort of noticeable way?

The answer is NO, you will not notice any difference. Any perceived difference will be due to how you may DRIVE with it on or off.

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?

I think any difference would be so small that it would take scientific instrumentation to detect... if there is any difference at all.

I put in a lightweight flywheel. There is no way I could rev THAT fast and hit my target RPM. I can't imagine that using SRM has any measurable affect on MPG. it will save money replacing your clutch though. Theoretically, it eliminates most of the wear on your clutch pads. (At lest on shifts)

I forgot to turn it on at the track once and almost left the pavement. (I usually DD with it off). I don't think it would take many trips off the track and into the (hopefully) dirt to negate your fuel savings

I get about 1 more MPG with the SMode off. I ran two tanks with on and two with off. It really depends on your driving style though. And to the earlier point, the four tanks were not controlled and identical. So I can't say 100% that MPG is better with off.

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.

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...

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

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.

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.

Is it?



:ugh2:

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

4 cylinders vs 6.

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.

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.

Beat me to it.

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

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

WIKEPIDIA has a pretty good explanation.

Thanks. i did know that to be honest.I have been driving cars with a manual gearstick for 29 years but never blipped the throttle on the downshift.Unless you are racing i don't think you are going to lose that much speed by not doing it and letting the revs catch up.I sometimes use it as a way to slow the car down too by changing down a gear and letting the clutch off.Not quite so easy in the 370z as the clutch is a bit high sprung and the biting point so small.

I will add i have had the rev match off for a few days and find the car a lot smoother to drive.Especially the first to second gear change.

wtf's with all this confusion driving a AT car... :shakes head:

With my previous cars (Audi Quattro coupe, Eagle Talon TSi and Celica GTS) I always rev matched and used the revs to slowdown the car instead of the brakes. But here I have learned that it is bad for the clutch (could be the reason had to get a new clutch for my Eagle Talon TSi way back when), which is more expensive then new break pads.

The main reason I rev matched, is that I am always in pursuit of the perfect drive (smooth shifts, smooth breaking, etc.) and the only way to make your down shift smooth is to rev match, otherwise the car will lurch.

When I first got the Z, I did not like the automatic rev matching, but only because I did not understand it and did knot how to properly use it. I used to turn it off all the time. But now after a few month of driving, I no longer turn it off and I like it a lot. It gives me those perfect drives more often.

As far the first to second shift, just hold the clutch in a bit longer for a two count, which will allow the S-match to catch up (it works on the upshifts too) and you will have a much smoother shift.

Look up "helper spring mod" in the DIY section to help with the "high sprung" clutch.

I got the Z specifically because it has rev matching. No other car in the price range offers it. The way I see it is that "good" tech is cool. Good being in the the users eye. This is good tech. I almost went with auto because the reviews on here said it was a good auto. Couldn't bring myself to do it. While I don't regret it, I should have at least test driven one.

Cooltoy is right on the money about 1st to 2nd shift. I found that under 3500 rpm requires the "two count." Generally true for 2nd to 3rd as well. Higher revs do not. Around 4500 RPM and above the engine RPM starts to reduce fairly quickly when you begin the shift. Change the shift style with the aggressiveness of the :driving:.

You may find that you don't want the mods.

ok let me explain this to all of u. It is all on the driver on how far he/she likes to put their throttle down, but wile in S-mode it is fixed that the rpms dont go lover than 2000 for example: to an idle of base 650rpm, nismos 700rpm wile S-mode is off. idleing at 2000 rpms means u burn 14.7:1 A/F ratio @ 2000 rpm wile in S-mode rather than base 650rpm, nismos 700rpm wile S-mode is off.

Just for the record i dont drive with S-Mode i just know how it functions and i dont hate it just never found my self using it.

P.S. this car is tuned from the factory to give 14.7:1 a/f ratio till 3200rpm, wich causes torque loss in low rpms, after uprev tune i found it that the engine has much better response when u start 13.7:1 a/f ratio @ 2000rpm.

You mean a video like this that I just took?

http://vid484.photobucket.com/albums...psny1q0e34.mp4

Pretty sure that's SRM allowing it to go below 2,000 RPM. ;)

Theres something in the manual about SRM holding a specific RPM dependent on the speed of the car for like 2 seconds before going back to idle.

if you downshift every single gear with s-mode for every stop or slowing down versus popping it in neutral with no rev matching technique, yea there would be some MPG drop.
depends on how much gas ur blipping. if ur asking if s-mode contributes to any change in timing or throttle response that might affect the MPG, no.

Don't read this as me being confrontational - I'm genuinely curious, because my line of thinking was different from what you've said. How is rev-matching bad for the clutch?

Reason I ask is because I always felt that rev matching would be better for clutch life because you would have more friction on the clutch without rev matching to get the engine speed to match the drivetrain speed.

The other piece of it is this - the way to save gas driving a manual is clutching into neutral and braking when you need to stop. Coast as much as possible. In the Z, for example, with SRM turned on, if you employ a lot of shifting into neutral, you will use more gas because the car will temporarily hold the revs (using the throttle) until the SRM system recognizes you're leaving the car in neutral. In this case, it's better to leave the system turned off. In any other scenario, it's apples and oranges.

bingo