d15b vtec needs 93 octane??

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regal1975

Junior Member
im curious if running a higher octane fuel is needed for this car.. according to the chart this motor only has 9.6:1 compression so i dont see why it would, but i figured id better ask before i run off and dump more money at the pump..
 
most vehicles don't benefit from running a higher octane. just stay away from shit like am/pm or arco. that gas is horrible and will ping with almost any octane.
 
and actually, if you do the math, it's not very much more expensive.. AT ALL to fill it with '92.
Stay with me:
average prices here in FL:

89- $2.80
92- $3.00
x
10 Gallons

89= $28.00
92= $30.00

Just think of it that... it's basically not any different, so if your car likes 92 better than 89, run it...?
 
w3rd... I run 91 all day long but I only pay like 5 cents more a gallon for it here in KS. If I had to pay a 20 cent difference I'd probably say fuck it but in my case I actually run 10.4:1 and even then it's not really vital or anything... I've run 89 no problem.
 
Andrew said:
and actually, if you do the math, it's not very much more expensive.. AT ALL to fill it with '92.
Stay with me:
average prices here in FL:

89- $2.80
92- $3.00
x
10 Gallons

89= $28.00
92= $30.00

Just think of it that... it's basically not any different, so if your car likes 92 better than 89, run it...?


it doesnt like it better. I used to have a rex with a D15B vtec.With that low compression your just wasting money.
 
Use 87-89 octane. In Japan they have higher numbers because of how they calculate their octane rating. In reality, they used the equivilent of our 87 octane there.
 
have you seen inside the throttle body on the jdm motors? fuckin nasty! their fuel filtration is horrible compared to ours.Unless your running 11. or higher its worhtless. you dont benifit from the higher grade gas with your motor. infact it could actually cause knocking. ive seen it happen before. dont know the scientific reason but i have known people to have that problem.
 
BlueCrxNC said:
Use 87-89 octane. In Japan they have higher numbers because of how they calculate their octane rating. In reality, they used the equivilent of our 87 octane there.

dude i was in Greensboros working awhile back damn thats:p funny to me.

back to the subject
 
Yeah I got my b16 in and I opened the throttle blade and there was a mound of black shit all the way around it.
 
^^^ thats what i saw inside an h22a. but anyway. just use the cheap stuff man. you'll be fine.
 
is the crappy ass gas in japan the reason they can only run their cars to 60,000 miles before being required to replace 'em?

i read somewhere that in japan they have to replace the engines after hittin' ~60K

kinda off the subject but still on lol
 
mustang67n said:
is the crappy ass gas in japan the reason they can only run their cars to 60,000 miles before being required to replace 'em?

i read somewhere that in japan they have to replace the engines after hittin' ~60K

kinda off the subject but still on lol

someone stop me if im getting to off the subject. the question has been answered.

uhhh i suppose thats the reason. i mean if you look inside you can definitly see trong build up. I cant imaginge what the pistons look like. the jdm d15b i had was covered in oil gunk inside the head. I mean bad!!! it wouldnt surprise me if they are killing those engines with their own gas.
 
regal1975 said:
im curious if running a higher octane fuel is needed for this car.. according to the chart this motor only has 9.6:1 compression so i dont see why it would, but i figured id better ask before i run off and dump more money at the pump..

87 or 89 is perfectly fine.

Taco15 said:
it doesnt like it better. I used to have a rex with a D15B vtec.With that low compression your just wasting money.

Yup. Higher octane on a D15B won't give you any more power than a lower grade that still won't detonate. The computer that runs the D15B isn't smart enough to adjust timing for knock and get more power from higher octane rated gasolines. Some engine do- D series engines don't.

BlueCrxNC said:
Use 87-89 octane. In Japan they have higher numbers because of how they calculate their octane rating. In reality, they used the equivilent of our 87 octane there.

They calculate their octane rating the same way- they just use a different part of the equation than we do.

The next time you go to the pump, look at the rating sticker. Below the number you'll ALWAYS (in the USA) see "R+M/2". That means (RON + MON)/2. RON = research octane number, MON = motor octane number. They're specific octane ratings that come from tests on standardized engines. Our pump octane rating in the US is an average of the two, while most of the rest of the world rates their gas using just RON. RON is typically 4-5 points higher than our pump octane number here in the US, and MON is usually about 10 points lower than RON.

Japan measures their gas using RON only, so when you see engine specs that say an engine requires 98RON, that's about equivalent to our 91-93 octane here in the USA. Our 87 would probably be about the same as their 92RON, another common rating.

More here if you want to read up a bit:
Octane rating - Wikipedia, the free encyclopedia

mustang67n said:
is the crappy ass gas in japan the reason they can only run their cars to 60,000 miles before being required to replace 'em?

i read somewhere that in japan they have to replace the engines after hittin' ~60K

kinda off the subject but still on lol

No, it's because of their tax system that surrounds cars... it's really expensive to own and drive a car in Japan, so people don't drive them for very many miles- plus there aren't nearly as many places to go so you don't see high odometer readings like the US- and so people buy new cars instead of trying to maintain aging cars with higher tax rates. Short car lifetime because of high taxes is also a reason why a lot of Japanese cars aren't superbly maintained. If you're going to pitch the car after 30-40k miles, why put a ton of money into maintenance? Just put that money towards another car. That's why you'll see a lot of gunked up JDM engines- not because their gas is crappy. It's not like bad gas is going to make your throttle plate area nasty anyway- there's only air going past there, unless you're having some serious backfire! Think about it!
 
yeah, thanks man, i always wondered why they got rid of their cars so quick. now it makes sense!
 
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