Honda Civic VX Premium Fuel

[rabbit640]

Anyone use premium fuel in their VX? Looks like I might have to:
http://www.wowt.com/news/headlines/Change-At-Nebraska-Gas-Pumps-224212541.html.

Not sure what I should do about this. I feel like 84 octane would screw up my VX, but clear 91 octane might screw it up even more!!!

I'd rather get a good fuel and get my VX to last a long time then have a crap out early on me. Need to update my profile btw. I have acquired a 1992 Honda Civic VX for $2000. Its red, all stock, I get 53 mpg (80/20 tons of city), it has 133,XXX miles. I'm shooting for 55 city and 65 highway. Spark plug wire kit is NOT stock. NGK blues are being shipped my way right now.

Please help!

[02ws6]

I bet the 84 would be fine considering the compression ratio of most hondas is only 9:1 but I'd go 91 if they aren't putting any ethanol in it.

[Ryland]

My VX runs best without ethanol and the mileage is enough better that it's well worth it.
When I have to fill up the gas tank on the truck at work I put premium in and notice the instant mpg read out jump up enough that I'm saving money.

[rabbit640]

Interesting thread on the effects of higher octane on lean burn: http://ecomodder.com/forum/showthrea...wer-12499.html

This thread on ethanol concerns me. Sounds like poison for cars older than 1995: http://ecomodder.com/forum/showthrea...age-18326.html

I'm definitely leaning towards the 91 octane fuel. As an added bonus 91 octane from shell has more v-power.

[rabbit640]

Max compression ratio for regular gas? [Archive] - THE H.A.M.B..

So apparently I should be running 91 Octane now!!!

This is for maximum efficiency and performance. However, given the cost of premium it is not "needed." Apparently, you multiply your compression ratio by 10 to find out your maximum efficiency octane.

Obviously the mpg and hp increase would not be worth the extra cost to you lucky individuals with 87 unleaded. Seeing as how I have no choice, I think I'm going to go with premium. Looking at my owners manual it says 86 octane or higher. It also says UNLEADED ONLY in all caps and bold. Also says this on the gas cap itself. Certainly seems like octane isn't a big deal to Honda, but ethanol is...

[roosterk0031]

The 84 is going to be blended with premium to make 87 or with Ethanol to make 87, don't think you see 84 at any pumps.

[some_other_dave]

Originally Posted by rabbit640

Apparently, you multiply your compression ratio by 10 to find out your maximum efficiency octane.

Compression ratio is only one factor in what octane fuel you need to run. There are lots and lots of other factors, from combustion chamber shape, to spark plug choice, to cam grind, to how good your cooling system is at preventing hot-spots, to if you are running boost.... No simple calculation can take those into account, so that calculation above is little better than a SWAG.

-soD

[rabbit640]

Just got off the phone with several gas stations in town. BP is the only station that does not use ethanol in their premium gas. Every other gas station in town uses at least 10% ethanol in all of their fuels. Decided to advance the timing on my VX (based on the advice of suspendedhatch). It should give me a small mpg boost, however the downside is that I will have to use premium fuel (but I have to use it anyways to avoid ethanol).

Whats weird is that when I checked the timing, it looked like the dizzy was all ready turned to max!?!?

[pgfpro]

Originally Posted by rabbit640

Just got off the phone with several gas stations in town. BP is the only station that does not use ethanol in their premium gas. Every other gas station in town uses at least 10% ethanol in all of their fuels. Decided to advance the timing on my VX (based on the advice of suspendedhatch). It should give me a small mpg boost, however the downside is that I will have to use premium fuel (but I have to use it anyways to avoid ethanol).

Whats weird is that when I checked the timing, it looked like the dizzy was all ready turned to max!?!?

I would check to see where true tdc is at.

First align number one cylinder at tdc by watching the rotor come into phase to number one on the dist. cap. Then pull number one spark plug. Then take a long screw driver or something that will fit into the hole of number one spark plug hole. Insert it into number one cylinder's spark plug hole and by hand turn the crank at the balancer bolt back and forth watching number one cylinder and the screw driver move up and down. Get it to the very top or highest point. Keep in mind there will be some dwell time at tdc so you have to find the middle.

Now check to see if the balancer is on the tdc mark. There are two marks (sometimes three) you want tdc not the advance mark.

What happens on some of the Honda's is the balancer will move within the hub a few degrees.

Also on the dizzys there are a few different types out there, Import, US Z6, A6 etc. So the three bolt tabs can be way different or just a little different.

[02ws6]

Good follow up. Usually if the dizzy is cranked all the way one way the timing belt os off by a tooth.