Subaru SI Drive

I found this article about SI Drive on the Subaru web site that explains it best (a lot of write ups I read got it half right or didn't explain it well enough) incase you're interested...

 

http://drive2.subaru.com/Summer07_whatmakes.htm

 

 

And if you can handle the painful marketing bollocks, heres the video on YouTube...

 

[ame=http://www.youtube.com/watch?v=QRhKUBX7l8M]SI-Drive, Subaru Intelligent Drive - YouTube[/ame]

My friends 2011 STI has this and he sees no difference in mpg between any of the settings. Is this all hype?

Definitely not all hype.

 

If you see that i offers up to 10% fuel savings, that would only mean 2.3 mpg better if you were to be normally getting 23mpg in s mode. That is definitely feasible.

Definitely not all hype.

 

If you see that i offers up to 10% fuel savings, that would only mean 2.3 mpg better if you were to be normally getting 23mpg in s mode. That is definitely feasible.

 

Interesting. Wonder what the map difference is between this and the Cobb Eco Tune. Which interestingly I get better MPG off their Stage 1 map then Eco.

Most of us get mpg on a tune then on the stock map.

 

I filled the wagon Tuesday after work. Today 90+ miles later the dash is still reading over 26mpg.

 

Not bad for 280whp

 

Oh Yea, my 05 wagon doesn't have one of those knobs.

 

My 09 Spec B has one, and I hate it. I wish they'd put the seat heaters back in the orginial spot instead of that usless SI knob. As soon as the blue light goes out, I go to S# anyways.

In the older vehicles with it, it's mostly a gimmick in my opinion. Lot's of articles make it sound like it transforms the car but really it's just 3 selectable throttle tables.

 

It does allow for a tuner to adjust each mode to deliver different boost. I've got mine set up so that I-mode is linear maxing at Spring pressure boost only (12-13psi), S mode is linear with full boost, and S# ramps up to full throttle very quickly and is not at all linear.

 

The fuel savings in I-mode comes from a flat spot in the DBW throttle table. If you're add more gas pedal you're not going to see any real savings. Cruising at 70 in any of the 3 modes is going to result in the same mpg. It's the slower ramping and flat spot that gives you better acceleration mpg, but again only if you're not just giving it more pedal.

 

In the 2014 forester xt that I drove, not only does it provide separate throttle tables but also separate selectable "gears" and shifting logic on the CVT. In that application it definitely does more to "transform" the car.

In the older vehicles with it, it's mostly a gimmick in my opinion. Lot's of articles make it sound like it transforms the car but really it's just 3 selectable throttle tables.

 

In the 2014 forester xt that I drove, not only does it provide separate throttle tables but also separate selectable "gears" and shifting logic on the CVT. In that application it definitely does more to "transform" the car.

 

If you have a 5EAT it also changes the shift logic. Its a gimmick with a manual, but makes a dramatic difference with the auto.

If you have a 5EAT it also changes the shift logic. Its a gimmick with a manual, but makes a dramatic difference with the auto.

 

Interesting. In my 05 my 5EAT has sport mode. Pretty much no matter how I drive it I get the same MPG, unless I'm WOT all the time.

 

The only times I've experienced two truly different motors, BMW M5, where you pressed a button to get the full 500hp and my Honda S2000. Both are pretty dramatic differences out of the same motor. The BMW is just insane while the Honda has a massive power spike at vtec cross over.

 

The different modes only seem to change throttle and possibly boost on my friends STI.

'I' mode learns how you drive and will adjust your throttle table accordingly but can learn up to 'Sport' mode throttle response. In all three settings you won't be able to achieve 100% throttle instantly unless you look into a DBW controller. Regardless, it is a bit nice to have SI Drive for a tuner because as mentioned above, you can also set different peak boost maps along with the throttle tables.

Cruising at 70 in any of the 3 modes is going to result in the same mpg

Completely agree and exactly what I've noticed.

 

However stop/start in traffic between I and S# is quite a difference because S# keeps the rev's a bit higher, its alot more tempermental on the throttle response - just touching the pedal gets it moving sooner = more fuel consumption. In traffic I don't notice a considerable difference between I and S though - 10% is probably accurate.

 

There is a significant difference in performance between the 3 modes though - especially from "I" to S or S#. Driving in "I" is like someone removed the turbo, drives like a normal aspirated car. Flick into S and its like a different beast. I don't find a massive difference between S and S# though.

I'm not sure about the Legacy, but my sti also has a light that tells you when to shift in "I" mode, which lights up right before you hit boost. I suppose that's part of the mpg saving feature.

Now, I don't know about you, but I sure as hell didn't buy a performance car to save fuel, let alone tell me when to shift. That setting is a waste.

I found this article about SI Drive on the Subaru web site that explains it best (a lot of write ups I read got it half right or didn't explain it well enough) incase you're interested...

 

http://drive2.subaru.com/Summer07_whatmakes.htm

 

 

And if you can handle the painful marketing bollocks, heres the video on YouTube...

 

SI-Drive, Subaru Intelligent Drive - YouTube

 

Good find, thanks for posting this...

Most drivers would just leave it in sport sharp or sport. Who plays around with it everyday. Same as your seat and mirrors etc. Leave it in one spot. Just a Gimmick,

 

23mpg on e85 and with or slightly over 300whp(as I dynoed with the Heavy 18in wheels)

I am one of the seemingly few people that really likes SI drive. I don't really consider fuel economy, for the different modes but use it to vary the throttle response to the type of driving I am doing (I switch modes on the fly every time I am in the car).

 

I-drive is perfect for stop and go traffic, I use Sport for open highway driving, and S# when I need to get somewhere in a hurry (but I probably use it <5% of the time). I mean sure SI drive is a little gimmicky but I think there is certainly some useful applications for it.

I am one of the seemingly few people that really likes SI drive. I don't really consider fuel economy, for the different modes but use it to vary the throttle response to the type of driving I am doing (I switch modes on the fly every time I am in the car).

 

I-drive is perfect for stop and go traffic, I use Sport for open highway driving, and S# when I need to get somewhere in a hurry (but I probably use it <5% of the time). I mean sure SI drive is a little gimmicky but I think there is certainly some useful applications for it.

 

All of this tech is in my right big toe

As soon as the blue light goes out, I go to S# anyways.

 

 

Everytime.

Great article. I keep mine in S mode

I love the SI drive. I got a couple more mpg last weekend when I put it in I mode.

Once I get tuned it will be nice to have 3 programmed tunes I can easily select from with the knob.

 

Most people but this car as a daily driver that's comfortable and has a little pep. Not as a sports car which it obviously isn't. So having theirs tame throttle options I think is a great idea.

My favorite part I'm sure will be once I get it tuned though.

Hum. I have SI drive as well. I used the AP to change the throttle response map and the torque curve. Well first I had to adjust a few things so I could pull off with my ACT HD six puck sprung hub and keep the revs between 1500 and 1700 rpm. I also think that the throttle angle/pedal relationship sucks..., so I adjusted it to open exactly as much as I pressed the pedal down. I noticed that the throttle was all over the map when I was holding the car still on a hill with clutch and gas..., so it was hard to hold postion. Now it feels more like a cable throttle.

Then I changed the torque request in each mode. For "I" mode I ramped the torque request up rapidly so I had more torque earlier but the throttle position is still linear, eg. .25 thottle is .25 pedal, .50 thottle is .50 pedal and so on. Now I down shift less and I have better response to light throttle inputs when I am on the Highway. I also raised the boost map to support it by making its boost curve maximum the same as the one for sport mode.

Of course the sport mode curve was changed to something else. I moved the max boost of the curve to midway between what the I drive setting is and the sport# setting is. I made the sport torque curve linear as well so there is more shifting but it is also way more fun because the boost level is greater on the top end. I modeled the sport# mode curve similar to the "I" mode but with way more torque and boost, sort of follows the max torque of the turbine, so it is savage and fun all the time. The car has three different characteristics. So it can be done if one tries it.

My AP was worth the cost, just to get my launch tamed with my HD clutch. It is smooth as butter now because I changed the torque demand where the OTS and original maps were to light with it.