Initial impressions from a first-time Si owner

[kritz]

Well mileage wasn't any factor in my buying decision. My WRX got 24 on a good day. I was surprised by the difference between this and my 15 Si which got around 31 on the same driving route. I assume it will be over 40 later on.

Sponsored

 

[Design]

The MPG is part gearing and part power delivery.

 

[kritz]

Strangely the Altima gets better highway mileage than the Sentra. The Nismo Sentra (SI competitor) is rated at 31 highway, 7 less than an SI.

 

[kritz]

DP

 

[ne0guri]

The MPG is part gearing and part power delivery.

Isn't this one of the reasons why they made the power band narrow in between 3-6? I had always thought that was for fuel efficiency.

 

[Design]

Isn't this one of the reasons why they made the power band narrow in between 3-6? I had always thought that was for fuel efficiency.

It's more a function of the turbo/sizing than anything else.

The Si's turbo has a more efficient inlet/impeller for better flow in the mid range.

 

[Milo & Miles]

Congratulations on the new Si!

It looks simply STUNNING in red! Glad you're liking it more every day!

 

[optikalillusi0n]

It's more a function of the turbo/sizing than anything else.

The Si's turbo has a more efficient inlet/impeller for better flow in the mid range.

Is this also the reason the 2015 SI requires premium fuel as opposed to the 10th gen just recommending premium fuel? Because of the size of the engine and turbo?

 

[kritz]

I was curious about why I could run 87 in my new SI too. I assumed the knock sensor is set up to let you do that.

 

[firsthonda]

Actually, I'm not too impressed with the MPG of the Si. Sure it makes about 20hp/tq more than my Altima, but weights 200lbs less, and has almost 1/2 the engine size (2.5 vs 1.5) I'm not really great with physics, but I expected it to be rated better. On the Highway, I regularly get in the mid 40's, and I get about 26 around the city. I'm also doing it on 87.

Maybe it's due to the Manual being less MPG focused than my CVT? Not sure. Either way for the Si MPG I feel shouldn't be the driving factor. I'd give up a few MPG for a bit more fun.

Yes manuals at one time were the fuel efficient choice. Now autos are that choice. Can't wait until honda uses the new 10 speed auto in an si type engine. Omg that be perfect

 

[Design]

I was curious about why I could run 87 in my new SI too. I assumed the knock sensor is set up to let you do that.

Probably a few variables ranging from the knock configuration to the Direct Injection setup. We'd have to ask Honda lol.

 

[zx2down]

Probably a few variables ranging from the knock configuration to the Direct Injection setup. We'd have to ask Honda lol.

That's almost exactly what it is. It's why Mustang GT's have run 87/91 that since like 2007 and for a while had 2 power ratings.

 

[Joker33]

Yes manuals at one time were the fuel efficient choice. Now autos are that choice. Can't wait until honda uses the new 10 speed auto in an si type engine. Omg that be perfect

Why would you want an automatic in a "sports" car? I absolutely hate automatic and cant ever see myself with another automatic of any sort other than a truck as that's virtually all they make in a truck!

 

[zroger73]

Is this also the reason the 2015 SI requires premium fuel as opposed to the 10th gen just recommending premium fuel? Because of the size of the engine and turbo?

The 2015 Si recommends, but does not require premium fuel - just like the 2017 Si. The computer will adjust timing to minimize detonation when using lower octane fuel, but with a decrease in performance and only by a limited amount. You're not at risk of damaging the engine or warranty denial unless you use less than 87 octane.

With that said, you'll get better fuel economy and full performance by using the recommended fuel grade. There's little excuse not to use what is recommended. It's also worth noting that unless a vehicle is designed to take advantage of premium fuel, it is a waste of money and can decrease fuel economy.

 

[Mick the Quick]

It's not about how fast it is though......

It's the motion of the ocea . . . . never mind.

Sponsored