Ok, i had a post a few weeks ago about a hesitation on cold startup.. Well... Normally, i used 93 Octane in my VTEC... well, the other day i had one bar of gas left... and w/o thinking, i filld it up with 87 on accident... Well, since then (which was 4 days ago) i havent had one hesitating startup... any ideas?
ps. i will add, that i did just change my oil and filter about a week ago... but i wasnt even due yet... was around 2000miles
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Last edited by preludatic; 07-10-2004 at 10:17 PM.
if you have a usdm h22 than yes using 87 would be better for your car. the higher octane would cause a hard start and poor gas milage so you should see an increase now with the 87 instead. if you have a JDM h22, you have to use a 91+
Originally posted by 92 SI Ludester if you have a usdm h22 than yes using 87 would be better for your car. the higher octane would cause a hard start and poor gas milage so you should see an increase now with the 87 instead. if you have a JDM h22, you have to use a 91+
That's directly opposite of what I have been told/known.
silverbullit, it says it on My Si, so I'm assuming it says it on VTECs as well.
Prelude2005, same here, I think ludester needs to slightly modify his post, it probably is better for cold starts because 87 will combust easier than 91, but no way is 87 better for the H22, there's a reason why Honda recommends 91+ octane for the H23a1 and especially the H22. I as well agree with yield, check your spark plugs.
yes it does say premium unleaded only. The reason i use 93, is because all of the gas stations around my town only have 87, 89, 93. Theres only one that has 91, and its clear on the other side of town.
while on the subject of gas........i've always filled with chevron gas in my lude.......but i used to have a camry and when i filled up with racetrac gas or something simliar cheap gas.....i would get better mileage out of it compared to chevron gas.......like almost 50 miles.......but in my lude i've always put chevron premium......i'm wondering if anyone has ever noticed a difference in chevron and other premium 93 octane gases? in milage, performance, etc...
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"I am a ricer because I have Z3 fenders" Bless Her Heart ORG
87 is not better to run in your car. The ecu will pull timing and hurt performance. I'm sure it will run smoothly and all but it will be at a reduced level.
The real problem is running 93 and not 91. I discovered this when running Ultra 94 on my stock 96 VTEC. I would experience this hesitation on acceleration and I could never figure it out till one day when I ran 91...problem solved and I never had the problem again.
Originally posted by Satan_SRV 87 is not better to run in your car. The ecu will pull timing and hurt performance. I'm sure it will run smoothly and all but it will be at a reduced level.
The real problem is running 93 and not 91. I discovered this when running Ultra 94 on my stock 96 VTEC. I would experience this hesitation on acceleration and I could never figure it out till one day when I ran 91...problem solved and I never had the problem again.
Originally posted by KB798
Wouldn't a 93 be better than a 91?
no. if a vehicle cannot sense higher knock ratings and advance timing to compensate then it only hinders performance. Cars that run on premium fuel are tuned for 91 octane. Running higher than 91 is harder to burn from a simplistic perspetive and causes unburnt fuel to be blown through the exhaust system and cat..often clogging them up. That's why running 100 octane or whatever will foul your cat in no time.
When you running higher octane you need to advance timing so the spark goes earlier as the combusiton takes longer and does make more power but you need to ignite sooner. so running higher than 91 result in increased incomplete combustion.
most engines only sense knock, and retard timing which only covers low octane situations.
Any company that markets 93 and 94 octane as adding performance is only speaking in half truths. Yes it makes more power IF you change compression/ignition timing etc to take advantage of it. However, very few cars have that ability, especialy since 96 when OBDII came in.
If you have OBDI, running a higher octane than 91 and advancing your distributor is a good idea though.
so i should be putting in 91 octane since i have a 94 si.....which means ODBI......right now i'm putting in 93 chevron gas.....so i should advance my timing? i know you can do this by messing with the distributor.......exactly how would i do this? or where can i find info on how much to advance?
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"I am a ricer because I have Z3 fenders" Bless Her Heart ORG
Originally posted by petern101 so i should be putting in 91 octane since i have a 94 si.....which means ODBI......right now i'm putting in 93 chevron gas.....so i should advance my timing? i know you can do this by messing with the distributor.......exactly how would i do this? or where can i find info on how much to advance?
dyno is the only way to really know what the effets are.
If you have stock compression and 91 is available I would recommend using it, you will make more power on the same timing assuming it doesn't knock which it shouldn't
Originally posted by petern101 while on the subject of gas........i've always filled with chevron gas in my lude.......but i used to have a camry and when i filled up with racetrac gas or something simliar cheap gas.....i would get better mileage out of it compared to chevron gas.......like almost 50 miles.......but in my lude i've always put chevron premium......i'm wondering if anyone has ever noticed a difference in chevron and other premium 93 octane gases? in milage, performance, etc...
or maybe you should consider you Camry is just going to get better gas mileage than your Prelude?
well my camry was a v6 5spd and had almost the same hp/torque numbers as my lude....but in the camry shouldn't the same octane gas from racetrac be the same as chevron......maybe its cause that techron stuff does better for engine but doesn't help with fuel economy.......cause same octane in same car should have similar results......in 3 years of driving that car.....i've noticed it many times......
on the note of dyno.....i want to but don't want to be dissapointed in #'s....
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"I am a ricer because I have Z3 fenders" Bless Her Heart ORG
just because it puts out the same hp doesn't mean it'll get you the same mileage, the 4th gen VTEC put out a tad bit more than the Grand Am GT (187hp i think), but I can guarantee you the grand am got worse mileage. I guess by that reasoning though, the Camry would be getting worse mileage, but it's still possible it got better mileage, depending on how you drove that compared to the Prelude, but also what type of driving you do, or did with that car.
I think the techron thing is nonsense, but that's just my opinion.
hahah my camry well.....it was a 2.5 liter.....basically it was a ricer killer.....i mean who honestly thinks a camry can go fast....esp a 89 model.....but i drove the same with both cars.....but they roughly get the same gas after having my lude for a month....yeah i'm gonna try to use 91 for awhile and see how that goes.....albertsons is close and i think they use 91....
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"I am a ricer because I have Z3 fenders" Bless Her Heart ORG
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