Premium Gasoline

[AccordRacing21]

Is it okay to run plus or premium in a stock A20 without damaging anything? I've been thinking about putting plus or premium in but I don't want to damage anything.

[Ichiban]

okay bud, here's the deal....

your car runs fine on regular, right? then stay with the cheap stuff. premium won't hurt anything other than be a complete waste of money. Premium is used for high compression engines that like to detonate on regular fuel. your engine doesn't need it.

[AccordRacing21]

I was just wondering if I would have any performance gains. And I'm not your bud

[white ricer]

premium is used for forced induction motors because it has a higher octaine level and wont detonate as easily. Technically there would be a horsepower gain but nothing worth paying 20 more cents a gallon..

[Ichiban]

No. There will not be any performance gains. Premium fuel has slightly less energy per unit of volume than lower grades...

edit: Premium or race fuel is used in engines that build way more hp from their higher compression (not necessarily forced induction), this offsets the slight power loss from the high octane fuel. These engines won't run on regular gas, the high compression would cause the fuel to detonate.

Forced induction engines typically have lower compression ratios.

bud.

[AccordRacing21]

It's nothing personal, you're just not my bud. I'm sorry.

[Ichiban]

i just hope i answered your question for you...makes sense?

[AccordRacing21]

Yep, I was understanding you until you called me bud, pal.

[visionguru]

From my experience, premium fuel is certainly better.
For my car, BP 87 octan gas, I got 30mpg, while BP 92 gas, I got 33mpg.
When driving at 70mph, the engine is around 3000rpm for 87 octan gas, but using 92 octan gas, the engine is running at about 2850rpm.

Just do the math, 10% increase in MPG, but the gas price difference is less than 10%.

Which is better? Premium grade fuel. Not only the cost, but also the benefit for the engine. Definitely not "waste of money".

[lostforawhile]

I run the 89 becauee 87 octane now is not the same as what my car was tuned for 20 years ago, with all the new pollution additives and crap they put in the gas now,not to mention dilluting it with alachol like they do,it's just not the same. thats one of the dirty little secrets about modern fuel,if you have FI it's not as bad,but these carbs are very sensitive to it. it really depends on what area you are in,like here in georgia during the hurricane gas shortage they brought in the non pollution compliant gas for a while,what a difference. modern fuel sucks ass. plus i have internal mods,but the fuel is just not the same,also the octane rating process has changed since 1986.so 87 is not really 87 anymore. 89 is closer to it.

[buds302]

ok here we go....the fight about what gas to put in your 20 year old car. ok look when i had my car it was an 89 i put 93 in it. the reason is... when the shitty fuel was in it the valves tapped when you went up a hill or you were pushin the car hard! now thats the reason i put high test in my car. i didnt care about the price. even when gas was up there in the 4 dollar range i still put high test in it cause i didnt feel safe listening to my valves tap goin down the road. call me stupid, call me crazy but that was my reason. and BTW i still do it in my civic even tho its prolly not worth it case its gonna blow up anyway the way i drive it!


oo look only 2 more till i make LX user!!

[gp02a0083]

carbs are very sensitive to it
yah i hear that my cuttlass's v-8 4bbl carb is sensitive to the stuff i usually buy mid grade b/c the cheap stuff makes it run bad

[AccordRacing21]

ok here we go....the fight about what gas to put in your 20 year old car. ok look when i had my car it was an 89 i put 93 in it. the reason is... when the shitty fuel was in it the valves tapped when you went up a hill or you were pushin the car hard! now thats the reason i put high test in my car. i didnt care about the price. even when gas was up there in the 4 dollar range i still put high test in it cause i didnt feel safe listening to my valves tap goin down the road. call me stupid, call me crazy but that was my reason. and BTW i still do it in my civic even tho its prolly not worth it case its gonna blow up anyway the way i drive it!


oo look only 2 more till i make LX user!!

I've been wondering why my valves tap. Like if I'm goin up a big hill on rpms below like 3500 or so.

[bobafett]

alright all u buds and dipshits and assholes... :D (jk)

the FSM states clearly to run 91 octane or higher in an 86 accord. :) sorry to burst all your bubbles.

now do 90% of us run regular, yes, and does it work fine, yes. but just so you are properly informed, honda intended us to all run 91 in these cars. funny huh?

btw i run 92 in my car, it knocks with anything less! :( i probably just depends on your timing and your mods whether or not premium will affect how the car runs, but mine is waaaay smoother on premium, and it knocks with anything less.

:) *the more u know*

[voiceinurhead05]

I Run 89 in mine. It's only 10 cents more per gallon, and it keeps the engine from bogging down on hills.

[lostforawhile]

I Run 89 in mine. It's only 10 cents more per gallon, and it keeps the engine from bogging down on hills.
one of the other problems now is that most fuel is formulated for fuel injected cars,since they inject fuel under pressure they don't require the same vaporization characteristic as carbs do, also in the mid eighties there were still a lot of land yachts on the road that required premium leaded fuel, since it was being phased out, the gas was formulated as a compromise and that fuel was what these cars were designed to run on. that fuel does not exist anymore. modern fuel is full of solvents and additives to keep fuel injected systems clean thats not the best thing for carbed cars. the alcholol they are blended with is also terrible for them. hate to say it but gas just isn't gas anymore. for a good note when i talked to the guy at pierce manifolds he said that the new webber carbs are made to run on the new fuels. but sometimes they still have problems with it eating seals in the carbs.

[buds302]

im gonna run to the sunoco in hagers town and get some 104 and see what happens!! lol

[Ichiban]

Low grade fuel doesn't cause "valves to tap" the sound you are hearing is DETONATION. Mechanical failure, misadjustment or freakishly large carbon deposits cause "valves to tap".

The only reason for using a higher grade of fuel is if you are having detonation, or a certain grade is specified (bobafett)

ps: the manual for my 81 specifies 89 octane while the manuals for the 82/83 call for 87. I believe the compression ratios are the same....

edit: heheheh....pal!

[lostforawhile]

oh i wasn't using the premium becuae of tapping,but because the fuel in 86 is actually closer to what 89 is now. it actualy says in my book that a light tapping noise under acceleration or going up hill is normal. thats the factory book. my 81 civics were noisy little buggers as far as the valve train,and they were mechanically perfect. some of the early hondas were just a bit louder then others. I noticed that having a very early version of the a20 the bs,it's a little noisier then the later ones. but there is nothing wrong with the motor mechanicaly.

[A18A]

91 is the lowest we can go here lol if we had 87 im pretty sure it wud be alot cheaper seeing 96 is $1.50 or sumting and 91 is $1.40 (was $1.33.9 last week, hate it when fuel gets to a high cost) so id say if this were last week 87 octane wud be about $1.twenty something...

[lostforawhile]

87 here is over two dollars a gallon

[A18A]

91 is $1.40/litre

[racerx]

For those of you willing to learn something cool:
http://www.autoclips.net/detail.php?id_video=3264

Octane ratings go like this:
The rating is simply a measurement of how stable the fuel is. The higher the octane, the less likely the fuel will detonate under high pressure and high heat situations.

If you have a low compression engine, your fuel will probably not detonate due to the fact that it does not create too much pressure or heat.
Therefore, your low compression engine will be able to choose when to light the fuel, because the fuel will never spontaneously combust.
The engine gets to use the fuel as efficiently as possible when it chooses the ignition timing.

Now, if you have a high compression engine, low grade fuel will probably combust due to pressure BEFORE your engine would like it to.
If you feed your engine with higher octane (more stable) fuel, your engine will get to choose when to burn the fuel, resulting in more efficient use of the fuel, and therefore more Horsepower and better gas mileage.

Low grade fuel in really high compression engines creates a knocking sounds (piston knock) because the fuel is detonating too early. It's pushing the piston down before it has reached TDC, and the pressure needs to go somewhere, so the piston usually just tilts and slaps the side of the cylinder.

If that same engine gets higher octance fuel, the piston is thrusted down after reaching TDC (as it should be) because the engine is now able to burn the fuel at the correct time.

Any questions?

[lostforawhile]

For those of you willing to learn something cool:
http://www.autoclips.net/detail.php?id_video=3264
Octane ratings go like this:
The rating is simply a measurement of how stable the fuel is. The higher the octane, the less likely the fuel will detonate under high pressure and high heat situations.
If you have a low compression engine, your fuel will probably not detonate due to the fact that it does not create too much pressure or heat.
Therefore, your low compression engine will be able to choose when to light the fuel, because the fuel will never spontaneously combust.
The engine gets to use the fuel as efficiently as possible when it chooses the ignition timing.
Now, if you have a high compression engine, low grade fuel will probably combust due to pressure BEFORE your engine would like it to.
If you feed your engine with higher octane (more stable) fuel, your engine will get to choose when to burn the fuel, resulting in more efficient use of the fuel, and therefore more Horsepower and better gas mileage.
Low grade fuel in really high compression engines creates a knocking sounds (piston knock) because the fuel is detonating too early. It's pushing the piston down before it has reached TDC, and the pressure needs to go somewhere, so the piston usually just tilts and slaps the side of the cylinder.
If that same engine gets higher octance fuel, the piston is thrusted down after reaching TDC (as it should be) because the engine is now able to burn the fuel at the correct time.
Any questions?I know this, what i was saying is the method used to calculate octane in 1986 was a little different then it is now. the modern fuels cause other problems in these older cars too,like i mentioned, the huge shift from carbs to fuel injection required a change in the way gas was formulated you can also run into problems with these engines too due to the fact they were made to run on the lean side, and the fuel vaporizing differently can put them over the edge, this can also cause a spark knock condition because the mixture is too lean.

[racerx]

and a lean mixture is a cause of detonation. thus, piston knock.
(or in a boosted case, thus boom)

[Bglad420]

Just put jet fuel in it................

[theDougler]

i use 87 because its cheap which 97.9/litre and i think 91 is 1.209/litre you guys think you got expensive gas think again, to put it into perspective its $3.72/gal for 87 and $4.60/gal for 91 in canada thats converted into imperial gallons. though not as expensive as NZ or Europe

[lostforawhile]

Just put jet fuel in it................uh,jet fuel is kerosene, like the engine treatment that was out that said in big letters "contains jet fuel!!
uh no thanks if i want kerosene in my engine i'll buy a diesel. now 100ll aviation fuel is a different story. thats some quality gas there,very strict formulation,and mostly made for old technology carbed engines.

[racerx]

AvGas is made for high compression, high performance airplane engines. it's basically as pure as gas can get. I use it once in a while, but that's because I have a cat replacement.

If any of you use AvGas and you have a cat, it will ruin the cat, so don't do it. Replace that thing with a test pipe, and then you're free to go!

And for those of you wondering where you can get 100 octane Low Lead (AvGas), go to the local airport where you see those little prop planes flying out of. You'll probably get better service/less hassle if you go to the small air strip meant mostly for the private pilot, rather than the local international airport. :)

Bring a 5 gallon gas can (or larger). The AvGas nozzle is basically the same size as a diesel nozzel and will NOT fit. So, either bring a gas can, or convert your filler.

(the above are things i wish i had considered the first time i bought that fuel... )

[87LXiR]

i run 91 no matter the price even when it was 3.59 dollars a pop(during the summer in cali). The car has given me no probles performance wise no stalling or sputtering while going uphill. it doesnt burn oil and runs clean and smooth. from my under standing(and i may be wrong) higher octane burns slower than lower octane (mili seconds) resulting in better performance(smoother and cleaner running but no increase in hp) i cant really remember why (its one of those little miracles of life)
But to get back to the main point it wont harm your engine and it will run better just dont expect an increase in hp:)
Oh and this doesnt really matter but i perfer 76 gas over the others call me paranoid but it my car seems to run better with their gas.

[racerx]

it WILL give you more HP, if your engine can appreciate it. (higher compression engines)

I guess no one watched that movie I linked...

[lostforawhile]

i run 91 no matter the price even when it was 3.59 dollars a pop(during the summer in cali). The car has given me no probles performance wise no stalling or sputtering while going uphill. it doesnt burn oil and runs clean and smooth. from my under standing(and i may be wrong) higher octane burns slower than lower octane (mili seconds) resulting in better performance(smoother and cleaner running but no increase in hp) i cant really remember why (its one of those little miracles of life)
But to get back to the main point it wont harm your engine and it will run better just dont expect an increase in hp:)
Oh and this doesnt really matter but i perfer 76 gas over the others call me paranoid but it my car seems to run better with their gas.are you running a carb or FI? I have noticed the same thing,only certain brands of gas around here are worth anything,it makes sense that a lot of manufacturers blend it different. also around here most of the stations are ownd by people of certain ethnic persuations,and it's a known fact that they water down the gas to make more profit. actually a couple of them were caught doing this not to long ago.

[Ichiban]

Low grade fuel in really high compression engines creates a knocking sounds (piston knock) because the fuel is detonating too early. It's pushing the piston down before it has reached TDC, and the pressure needs to go somewhere, so the piston usually just tilts and slaps the side of the cylinder.

If that same engine gets higher octance fuel, the piston is thrusted down after reaching TDC (as it should be) because the engine is now able to burn the fuel at the correct time.

Any questions?

...a few, yes...

gasoline engines are designed to burn the fuel, not detonate it. any detonation will cause that "diesel knocking" sound. this is the shock wave bouncing off the inside of the cylinder.

with a running clearance of four to six (honda specs anyone?) thousandths of an inch, your pistons should definitely not be tilting and slapping the cylinder wall. usually, only a severely worn piston and bore will do this.

What is your timing set at? Most engines i've seen are timed to fire at about 8 degrees before top dead center at idle. as your rpm increaces the ignition system may advance that as much as 40 degrees. why? the idea is to get peak cylinder pressure at around 14 degrees after top dead center, however as the gasoline is burning, it takes time to develop peak pressure. as you speed up, the fire has to be lit earlier, as your piston is travelling faster, but the rate the fuel and air burn at stays the same.

[lostforawhile]

i'm not talking about a loud knock,i'm talking about the light tapping you hear while under load or going up hills,according to the owners manual it says it's normal to hear this under those conditions. it seems to be more common on the carbed engines. I drove one of these when it was brand new in 89 and it did the exact same thing. I just wish I had bought it.

[Ichiban]

my toyota rattled a bit when i drove up hills when it was down on the coast, it also sounds like a diesel if you lug it around 200 rpm. i've noticed most of em do that. also, my buddy put an fi block 300 six into his ford and carbed it and that thing is constantly knocking and pinging (and dieseling) even with 91in it. i understand the fi engines had higher compression than the carbed ones did...

[racerx]

...a few, yes...

gasoline engines are designed to burn the fuel, not detonate it. any detonation will cause that "diesel knocking" sound. this is the shock wave bouncing off the inside of the cylinder.

with a running clearance of four to six (honda specs anyone?) thousandths of an inch, your pistons should definitely not be tilting and slapping the cylinder wall. usually, only a severely worn piston and bore will do this.

What is your timing set at? Most engines i've seen are timed to fire at about 8 degrees before top dead center at idle. as your rpm increaces the ignition system may advance that as much as 40 degrees. why? the idea is to get peak cylinder pressure at around 14 degrees after top dead center, however as the gasoline is burning, it takes time to develop peak pressure. as you speed up, the fire has to be lit earlier, as your piston is travelling faster, but the rate the fuel and air burn at stays the same.


So your question is................???

Or are you just confused about the whole thing?

You understand timing and the burn process, but the fuel WILL detonate if it is unstable enough. I know your piston is reeeeeeally close to the wall, but it WILL tilt and slap.

Besides that, when your fuel detonates, it creates a LOT more heat than a regular burn. This heat will cause your piston to heat up and expand a little further than it was designed to, and it will start to scrape the cylinder walls. Enough of this kind of abuse and you have plenty of room to start knockin.

[Deadhead]

wow, makes me happy that I changed from regular to midgrade... i didn't like that knocking/tapping noise.

[Ichiban]

yes i agree that detonation wrecks stuff, but under the proper conditions a brand new engine will rattle and knock from detonation, even with the perfect pistion to cylinder wall clearance. The most common damage from detonation (at least from what i've actually taken apart and seen) is a piston with a big hole burnt in it. the cylinders have been fine, except for the boat motor i wiped out where everything inside was trashed.

[SteveDX89]

To everyone who has tapping with 87 octane, check your ignition timing. When it's correct, no tapping.

[racerx]

detonation usually causes the pistons to get too hot, expand, and scrape the cylinder walls. I've seen this many, many times. If it goes on too far, or has serious detonation too quickly, THEN you will put a hole through the piston, if it's a weak one...

[Blkblurr]

No matter what octane fuel you are using, the higher the number, the more difficult it is to burn. If higer octane makes your car sound better then use it. I seriously doubt if higher octane makes any engine run better unless it's having pre-detonation problems. The reason car makers specify a minimum octane rating is to keep your engine from being damaged from pre-detonation. The higher octane numbers does not mean the gas is more powerful. It's actually the opposite as someone mentioned earlier.

[87LXiR]

are you running a carb or FI? I have noticed the same thing,only certain brands of gas around here are worth anything,it makes sense that a lot of manufacturers blend it different. also around here most of the stations are ownd by people of certain ethnic persuations,and it's a known fact that they water down the gas to make more profit. actually a couple of them were caught doing this not to long ago.
Im FI and yeah ive had watered down gas the car really sucked (there was no power). Andim glad they caught the ones doing it by where you live

[racerx]

No matter what octane fuel you are using, the higher the number, the more difficult it is to burn. If higer octane makes your car sound better then use it. I seriously doubt if higher octane makes any engine run better unless it's having pre-detonation problems. The reason car makers specify a minimum octane rating is to keep your engine from being damaged from pre-detonation. The higher octane numbers does not mean the gas is more powerful. It's actually the opposite as someone mentioned earlier.

higher octane WILL give you more power, IF your engine can't control the lower octane fuel. see previous post with movie link.

[Ichiban]

aaughh...

all that movie shows is how the high end modern car's computers with knock sensors will dump the timing, richen the mixture and use more egr so it can tolerate the low grade fuel. of course you will get more power and fuel mileage out of the high octane fuel because thats what the engine was designed for. since our cars aren't built like that, the lowest grade of fuel the engine will tolerate WILL give you the most power (cause they won't adjust for it). Ethanol has somewhere around 1/3 to half the combustive energy of gasoline (tried to find specific numbers to prove it) and a lot of high octane fuels are ethanol blended to raise the octane rating. so unless you have the compression ratio to "appreciate" and require the anti-detonating characteristics of the high octane fuel, it does you absolutely no good.

yes, detonation can overheat your piston to the point it scuffs the cylinder, but holes, broken ring lands and spark plug electrodes are way more common. and that rapping sound is NOT piston slap, it's the pressure wave of the detonation smashing off of the inside of the engine. Piston slap usually goes away once an engine warms up as the piston expands to fill the bore.

anyways, i could care less what kind of fuel you put in your car, its not my money.

[racerx]

well, my prelude's engine has 10.3:1 compression (built) so I use 93 octane. It definately makes a difference.

I would wager if your A20 is worn and your compression is low, yeah, low grade works just fine. If your engine is new and and high compression like mine, premium works better.

[lostforawhile]

what i'm trying to say is the octane rating system is different now,modern 89 is closer to what 87 was in 1986. the things that modern fuel is blended with make it more prone to detonation in non computer controlled engines,it really doesn't afectect fuel injected cars because they can adjust for it. you have to understand the fuel companies really could care less about people with carbs,it's such a small percentage of cars that they could give a rats ass less. some of the solvents in it will also tear up the seals in a carb in a hurry. when i lived in Atlanta we had to use that pollution compliance gas,and I was replacing some seal or another on my carb every couple of weeks. I finally had to order a sheet of buna rubber and make a gasket for the top hat.

[Blkblurr]

well, my prelude's engine has 10.3:1 compression (built) so I use 93 octane. It definately makes a difference.
I would wager if your A20 is worn and your compression is low, yeah, low grade works just fine. If your engine is new and and high compression like mine, premium works better.

You get more power with higher octane only if it was pre detonating with lower octane. Don't confuse the increase in power because of higher compression. The BTU output of higher octane fuels is less than lower octane fuels. Ask any top fuel people. they will tell you this. You need to have a lower flash point in your fuel when running higer compression. Compressing the air more causes it to heat up more making it detonate before the spark plug fires. The detonation happens from heat left from the prrevious burn plus the heat generated from compressing the air in the cylinder. If you raise the flashpoint of the fuel (higher octane) it makes the fuel detonate with the spark plug firing instead of firing randomly due to high heat.

[racerx]

yes.... we've established this... lol, i think we're seeing eye-to-eye here.

btw, what do you think of your S2000? I'm seriously considering buying a new one myself. Do you really like the black, or do you wish you went with something else instead?

[Blkblurr]

I love the black S2000 because it just looks better to me than the others. It is very difficult the keep clean though. If you buy one get the clear film over the front end to protect from rock chips. I highly recommend it. it's the most fun car I've ever driven.

[racerx]

right on. i might be getting a black audi TT though... not sure...

[Blkblurr]

If you can, buy the S2000. It will kick the TT in the ass both in accell and handling. The 6 speed tranny has the best shifter in the business.

[racerx]

i don't think so... especially up at the altitude that i'm at. i've driven both and the TT owns the S2000 in acceleration. (6-speed as well, 225hp)
and it's easier to get more power with an engine that's already turbo

[AccordRacing21]

Filled up my car with Premium the other day and it made a huge difference. Much more responsive.

[3rdgenhatchDX]

And I'm not your bud


AHhashahhdfsasdhfhawhwefhwROFL!!!!!!!!!!!!!!!!!!!! !!

did it really make a big difference? was it worth the extra dough?

[Cheeseburger]

u can feel it. it feels like its a whole different car.

[racerx]

tis true. i went down to texas the other day and they only had 90 octane...
90!!!!!!!
not even 91.

my audi's gas cap has the same 95/98 sticker that we saw in the movie, and then i had to go to 90...

anyway, when I came back home, I made sure to fill up with 93 and it was totally different. i was thinking something happened to my car on the drive cuz it was all slow (well, not slow, but slower). but everything's cool now.

[3rdgenhatchDX]

so will it mess with my carb? i figured it would be okay...

[Cheeseburger]

it should be ok with a carb.

[bigskylxi]

From my experience, premium fuel is certainly better.
For my car, BP 87 octan gas, I got 30mpg, while BP 92 gas, I got 33mpg.
When driving at 70mph, the engine is around 3000rpm for 87 octan gas, but using 92 octan gas, the engine is running at about 2850rpm.
Just do the math, 10% increase in MPG, but the gas price difference is less than 10%.
Which is better? Premium grade fuel. Not only the cost, but also the benefit for the engine. Definitely not "waste of money".

Dude, that makes no sense. If your car runs 3k rpm at 70, its 3k rpm no matter what fuel. A transmission has gear ratios, if the engine rotates a certain speed, the wheels turn at a certain speed, fuel has no effect on that.

[gfrg88]

lol, yeah hes right, i didnt read that before but now that i do i think its funny :lol:

[speedpenguin]

On the quality of gas, if you have FI, then read this. (http://www.toptiergas.com)
Car manufacterers recently set a voluntary standard on what additives will be added to fuel to keep deposits from forming in your engine. It's called Top Tier, and it's great... If you have FI. If you're carbed, stick to the regular stuff.

[89AccordResto]

Yep, I was understanding you until you called me bud, pal.

Well good ole buddy, least you understand it then, skippy. :cheers:

[89AccordResto]

I Run 89 in mine. It's only 10 cents more per gallon, and it keeps the engine from bogging down on hills.

Wrong. The only thing that higher octane does it make it HARDER to ignite. You will actually LOSE power by putting in higher octane than you actually need in an engine. Use the factory suggested octane fuel for the BEST performance. If your engine is modded, it could be a different story. But you want to use the LEAST amount of octane that you can get away with, ie, no knocking.

[89AccordResto]

To everyone who has tapping with 87 octane, check your ignition timing. When it's correct, no tapping.

Ding ding ding. We have a winner. Higher octane is pointless unless you have a high compression engine or boosted or something.

[detroit313]

read this dickheads!

http://www.autobytel.com/content/shared/articles/templates/index.cfm/article_page_order_int/2/article_id_int/890

[speedpenguin]

On that note, read the blog in my sig

[Strahan]

What really makes me laugh is when I hear people go on and on about the higher costs of running premium.. around here, the difference is no more than twenty cents at most. If you get sixteen gallons, that's a cost increase of $3.20. Whoop-de-do heh.

[Ichiban]

read this dickheads!
http://www.autobytel.com/content/shared/articles/templates/index.cfm/article_page_order_int/2/article_id_int/890

...like I've been saying all along.