Honda puts 87 in these cars when you get them, unlike the past Si these cars don't have a requirement to run 91 or above. Before he moved over to tuning on Motec, Vit did some testing and tuning with the Si and he made more power by simply switching to premium grade fuel. He blogged the results on his page: http://blog.vittuned.com/introducing-the-2017-civic-si/
Yeah it kinda does say to use premium fuel in the Si. Who said Honda put in 87? Sounds like a lie. I'd love to see some factual evidence. Either way, I've been using 93 since day 1 because that's what Honda saysUmm well, I have an 18 Si and in the manual it say 91 octane or higher in Sport mode and also says premium fuel recommended right on the gas door.
Read the blog from Vit I posted, I have a few friends who work at Honda as well they don't pay importance to make sure your car has premium when they fill it for you to drive it off the lot. My previous Hondas were an RSX Type S and 9th gen Civic Si, their manuals read that premium is required while ours only indicate that it is recommended. The Si is not much different than the lower trims unlike the past Civic Si models, 91 or higher is still better for the motor absolutely. I went through my fuel tank fast and took it easy on the car when I drove it off the lot, as soon as I pumped 92 into it after that it felt considerably more peppy. Regardless I am not debating whether you should use premium or not, I am simply saying when running premium the car seems to make more power than the advertised numbers and people have reported having clutch issues fairly soon. More people that Vit have dyno'd the car and it seems to be a little underrated since it seems to dyno very close to the crank rated numbers.Yeah it kinda does say to use premium fuel in the Si. Who said Honda put in 87? Sounds like a lie. I'd love to see some factual evidence. Either way, I've been using 93 since day 1 because that's what Honda says
Note some quotes from this thread.27k using ktuner 23psi. i am not some tool that drops the clutch off the line just to hear the tires scream. done better than 250k on the same clutch in my previous car driving it as i do the civic now.
i can make the clutch slip on command in 4th 5th and 6th by using full boost around 4000rpm.
The stock clutch is underspecced when 40hp 50tq is enough to make it go this fast.
and, no, i have never smoked the clutch. i did break it in gently for 700k.
gettin tired of people saying its only slipping because of abuse.
I agree but if you look at it from a manufacturing angle 8% is pretty high failure rate hahaWe all know the clutch is a weak point of the transmission and that's not just a Civic issue. I mean a lot of it depends on driver skill, driving style and how much power you're outputting.
For shits and giggles, I just went through my tune reliability thread to see how many people mentioned they were experiencing clutch slip on the stock clutch.
45 out of 578 tuned manual owners (1.5T Si & Non-Si) mentioned stock clutch slippage issues. I know that's not scientific, but still, 8% having issues doesn't seem like a massive problem.
Sure, if those were factory tuned numbers but that 8% slippage rate is for stock clutches on tuned cars.I agree but if you look at it from a manufacturing angle 8% is pretty high failure rate haha
My clutch JUST started slipping over the last few months, and only on map 2 and 3 of the TSP Stage 1 tune.
2019 Si
Bought brand new in September of 2019
Now has:
48k miles.
1 track day
TSP Stage 1 since 15k miles.
PRL Cobra Street MAF
27Won:
Turbo Inlet, Downpipe, Frontpipe, and intercooler
Acuity Stage 3 shifter (not sure if that matters)
I've driven the car based on everyone here's recommendations by avoiding WOT under ~3200 RPM and avoiding WOT in 6th entirely, and 5th for the most part.
I know each clutch is different but I've beat on this thing between 3500-6200 RPM in 2nd, 3rd, and 4th and everything has been fine until lately. I'm happy that its lasted me almost 50k miles with how much I've done to it.
Damn. I thought I had patience!!27k using ktuner 23psi. i am not some tool that drops the clutch off the line just to hear the tires scream. done better than 250k on the same clutch in my previous car driving it as i do the civic now.
i can make the clutch slip on command in 4th 5th and 6th by using full boost around 4000rpm.
The stock clutch is underspecced when 40hp 50tq is enough to make it go this fast.
and, no, i have never smoked the clutch. i did break it in gently for 700k.
gettin tired of people saying its only slipping because of abuse.