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What do you get for mpg

I highly recommend using premium ALL the time. The cost of premium is rarely $0.30/gallon more than regular 85 octane. For our NSX's 14ish gallon tank, that's only a $4.20 difference. Heck, its only a $6.00 difference for the entire tank of my 20 gallon Expedition. I usually see a $0.20 difference which puts the cost at $2.80 and $4.00 respectively.

Is $2.80-$4.20 worth it? A $6 difference is worth it to me.




0.02
 
It's my understanding that the ONLY purpose of higher octane gas is to prevent knock and detonation.

If the NSX can run on 87 without the aforementioned ailments/events then the said octane is suffice.

Additional octane will not give u more power, but the potential to increase boost, compression ratios with a taller threshold.

Majority of NSX owners are not FI or running more compression............
 
BATMANs said:
It's my understanding that the ONLY purpose of higher octane gas is to prevent knock and detonation.

If the NSX can run on 87 without the aforementioned ailments/events then the said octane is suffice.

Additional octane will not give u more power, but the potential to increase boost, compression ratios with a taller threshold.

Majority of NSX owners are not FI or running more compression............
Click to expand...
As engines get hotter, the threshold for knocking goes down. If its hot out, if you drive your car hard, if you track it, if you run at high rpm, etc... All increases the potential for knock, even stock. While the stock ECU takes measures (to a degree) to prevent damage, these measures result in less power, but at an extreme, can still cause engine damage.

If you baby the car and never rev it out (which is also a bad thing) sure you could get away with 85 octane with probably no problems.

91/Premium has more detergents = cleaner motor, and theirs no reason not to spend a few more bucks to run it. If you don't want to, by all means its your car.
 
FXMDBilly said:
As engines get hotter, the threshold for knocking goes down. If its hot out, if you drive your car hard, if you track it, if you run at high rpm, etc... All increases the potential for knock, even stock. While the stock ECU takes measures (to a degree) to prevent damage, these measures result in less power, but at an extreme, can still cause engine damage.

If you baby the car and never rev it out (which is also a bad thing) sure you could get away with 85 octane with probably no problems.

91/Premium has more detergents = cleaner motor, and theirs no reason not to spend a few more bucks to run it. If you don't want to, by all means its your car.
Click to expand...

I was out in the middle of nowhere Nevada a few years ago running on fumes, ~ 50 miles with the gas light on. Came up on a gas station that sold only either 85 or 87 octane. So I gassed up with a good 1/4 tank to get me to a real town. Drove it like normal in the 115+ degree heat that summer, didn't baby it and it still drove ok and sounded ok all the way to Vegas where I filled up with Chevron premium. Car proved to me it could do alright if I had to. Definitely don't plan on doing that again.
 
When I first got my stock '94 last September, I was getting between 20 to 22 MPG. However, after getting 17/18 235/275 upgrade on tire, and upgraded to tubi exhaust, I am down to 18MPG in combine city/freeway driving. The only thing that I think I do lose MPG is that on the day I drive the car in the morning, I let the car warmed up for about 3 to 5 minutes.

On the side note, I know it is not a carburator car so it doesn't need the warm up. But I just found it drive smoother if I do. Does anybody else do this too?
 
Doraemon said:
When I first got my stock '94 last September, I was getting between 20 to 22 MPG. However, after getting 17/18 235/275 upgrade on tire, and upgraded to tubi exhaust, I am down to 18MPG in combine city/freeway driving. The only thing that I think I do lose MPG is that on the day I drive the car in the morning, I let the car warmed up for about 3 to 5 minutes.

On the side note, I know it is not a carburator car so it doesn't need the warm up. But I just found it drive smoother if I do. Does anybody else do this too?
Click to expand...

How long has it been since your spark plugs have been changed?

I let my car idle for about 2 minutes and thats about it.
 
Supercharged (523rwhp), 6-speed: Roughly 18.5 mpg mixed (ranges between 17.5 and 21.5 mpg). I have yet to take it on a long trip to see what I can get out of it.
 
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BATMANs said:
It's my understanding that the ONLY purpose of higher octane gas is to prevent knock and detonation.

If the NSX can run on 87 without the aforementioned ailments/events then the said octane is suffice.

Additional octane will not give u more power, but the potential to increase boost, compression ratios with a taller threshold.

Majority of NSX owners are not FI or running more compression............
Click to expand...

The NSX is running "more" compression compared to other cars, especially those that do not require 91+ octane fuel. The NSX is made to run on premium fuel, but will run on lower octane fuel if one finds oneself without option. This is because it has a system in place that retards timing when it does sense knock to save your engine from damage. It is not meant to run on lower octane petrol for extended periods of time.

91+ Octane fuel is not a "performance" fuel to be used solely for modified cars. Many cars require 91 octane straight from the factory, and the NSX is one of them.

I also own a Legend which has a lower compression engine than the NSX does but still requires premium fuel. On the Legend forums, many have tried running lower octane fuel, but what most have found is that while the car does run just fine (for the most part), the money saved is negligible as it appears to negatively affect mileage.
 
CDX_NSX said:
91+ Octane fuel is not a "performance" fuel to be used solely for modified cars. Many cars require 91 octane straight from the factory, and the NSX is one of them.
Click to expand...

This is a good point. There is no more "energy" in higher octane fuel than is found in fuel with a lower octane rating. Octane is simply the measure of a fuel to detonate at a higher temperature or pressure. Our high compression engine requires higher octane to stop pre-detonation.
 
i was getting 22 before putting the blower on the car.

16.5mpg for years. Then went to the AEM FIC and got a new tuner... went to 20 mpg at 380 rwhp.

Now i'm at about 18 mpg city driving at 425 rwhp with 500cc injectors and a walbro HP fuel pump. I have yet to drive it a full tank resisting the urge to drive aggressively... so i don' know what my mileage might climb up to.
 
When I bought my '94 auto it was all stock it would get mid to low 20's around town and a consistent 27mpg on trips.

I bolted on a cat back GT-One exhaust and I could get 30mpg on the long trips.

Now with low boost CTSC, DC sport headers, test pipes and an RS*R exhaust I'm back to 27mpg on the hiway and low 20's when pushing it on shorter trips.

I think it could do better on long trips but I have no self control when it comes to accelerating.
 
You guys need to get on Fuelly.com! It's a great site used to track vehicle MPG for every make and model so you can see some real world results. I'm currently the only NSX registered.

You can see my fuelly breakdown here. You can see that my average MPG is around 21.9 MPG with my best being 25.1 MPG. My average would be quite a bit higher, but if you look in my history, I had one day down in Branson, MO for Branson Z Fest in which we spent ALL day driving spiritedly through twisty roads and then finished up the afternoon with a day at the drag strip in which I got 17.6 MPG.

I dunno how you guys do it with the high 20s, low 30s. I have stock gearing and a relatively stock NSX (Cantrell AIS and Unifilter is my only power mod) and even driving on the highway setting the cruise @ 70 MPH I was only able to manage 24.4 MPG on my way back from Branson, MO to Kansas City. Regardless though, I'm happy with my mileage in the NSX... It typically gets 2-3 MPG better than my M3, which I use for the daily grind.
 
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I get low 40's....
tornado.jpg
 
peiserg said:
i was getting 22 before putting the blower on the car.

16.5mpg for years. Then went to the AEM FIC and got a new tuner... went to 20 mpg at 380 rwhp.

Now i'm at about 18 mpg city driving at 425 rwhp with 500cc injectors and a walbro HP fuel pump. I have yet to drive it a full tank resisting the urge to drive aggressively... so i don' know what my mileage might climb up to.
Click to expand...

That's tough to hear that the CTSC guys get worse mpg, but 20 mpg for a 400 hp car is not bad at all I think. I really would like to see more input from the boosted guys, turbo and SC. I've always get 24 mpg, for all city, or mixed. Even with agressive driving, never less than 23 mpg. If it's straight highway, I can get 28-29 mpg going 75ish. I would really like to know what boosted NSX are getting with regular daily driving and not so much of just pounding every gear cause of the rush from the boost...
 
LooseNut said:
When I bought my '94 auto it was all stock it would get mid to low 20's around town and a consistent 27mpg on trips.

I bolted on a cat back GT-One exhaust and I could get 30mpg on the long trips.

Now with low boost CTSC, DC sport headers, test pipes and an RS*R exhaust I'm back to 27mpg on the hiway and low 20's when pushing it on shorter trips.

I think it could do better on long trips but I have no self control when it comes to accelerating.
Click to expand...

That is INSANE. You must drive with a raw egg taped to your gas pedal.
 
Just got my 91 - it has comptech headers and a later model exhaust system and a Danli chip and air intake. I drove it back from Nashville to Atlanta this weekend exactly 200 miles from point to point and did it with a half tank - that's about 28+ miles per gallon based on a 14 gal. tank and that was from reading here. For some reason I thought our tanks capacity was 17 gallons. If thats the case then I only got 23.5 miles per gallon.

Anyone sure what the capacity is??? I could be wrong. It does very well but I'm expecting somewhere around the high teens in town. Combined city/hwy - I bet it would be doing good the way I drive mine to get into the 20s. My old 325 is got an average of 23.5 or so combined. Bimmers get very good mileage. My 530i with automatic got 30 mpg on the highway on trips - it was great. But if our tanks only hold 14 gallons them like I said it was over 28 mpg.

If I drive it like I did yesterday it'll be more like 16, but it sure was fun! That's about what my wifes RL gets mid to upper teens in town.
 
500+ miles is entirely possible, I have done 750km between fill ups which is very close and the tank was not empty.

My best is ~35mpg with almost 100% highway driving. ECU/Headers/Exhaust are aftermarket, speedo calibrated to GPS and using premium fuel. No wonder the Honda Insight was discontinued :smile:
 
OzzieJohn said:
500+ miles is entirely possible, I have done 750km between fill ups which is very close and the tank was not empty.

My best is ~35mpg with almost 100% highway driving. ECU/Headers/Exhaust are aftermarket, speedo calibrated to GPS and using premium fuel. No wonder the Honda Insight was discontinued :smile:
Click to expand...

What speeds?
 

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