Simple Questions (kinda long, plz help!)

[TheMutt]

Okay I've been noticing some things with my car and I just want to see what you guys have to say about some of it.

First of all, I'm having some gas problems. The other day I decided to switch to the good stuff so I started pumpin in premium when my tank was nearly empty. Well I'm not sure if this is when my problem started or if it was just coincidence, but now it seems like I'm getting really bad gas mileage. Like I went through nearly a quarter tank and only got 40-50 miles. Maybe I'm just being kinda picky because that almost sounds right or maybe its just the traffic, but that's kinda bad isn't it? I've gone so far as to nearly completely stop using my A/C, only sometimes while in bad traffic or going fast where the wind is annoying I'll put it on low. But is the premium gas (93 octane around here I believe) a factor in the pitiful mileage? After all that's one of the reasons I wanted a honda in the first place.

I've gone 2200 miles on my EP over the past 2 months so I probably need a good oil change. (Think I read before someone said this would help with the gas guzzling.) What is everyone's choice for a replacement right now? And when is a good time to change out the tranny fluid?

Next is some grinding I've been having. It's getting kinda bad, at first it would only be maybe once a week at most and it was never that bad so I'd just put it off as my inability to pay attention to my driving. But lately it's been every few days or even consecutive days I'd grind and it's always 2nd gear. ALWAYS.

Now for something on modding my Ep. My Injen race intake thingy will (hopefully) be on within the week, and my next plan was to get a good header and midpipe. Any suggestions?

Also something that bugs me a lil bit, has anyone else noticed that our 1st gear is pretty much useless for anything other than making our car sound fast?

[David K.]

I don't think the premium should affect your mileage too much, especially in our Texas heat. If you've been using the same brand try switching. I run Mobil 1 synthetic oil and have been very pleased with it. It should also help with your mileage (in theory). The grinding is probably your synchros in the tranny; I had mine replaced and so have many others as this seems to be a common problen in our car. As far as the header goes, if you want top-end power the HP header is good and cheap. The DC, Comptech, or Borla will give you better low and midrange pull. If you think our 1st gear is too aggressive, go with the HP to tone down the low end grunt. I have a 2.25" midpipe on my car and am very happy with it. Mandrel bent or cruch bent is up to you; both work well.

[TheMutt]

Wow thanks for the uber-fast reply just a quick follow up though. With the 2.25 midpipe and one of those headers do you think it would be very loud? And in the future if I decided to drop would I have to worry about scraping?

[blueiedgod]

in actuality if you drive at speeds above 55 mph, your gas mileage will siffer greately from open windows than from having a/c on. Just think of it as a parachute when you have front windows down. If the rear quater windows opened a bit it may have evened out the gas melage, but since they are fixed, you are dragging a parachute behind you everytime you drive with the windows down.

Poor gas mileage may be due to low oil level. Check your oil at every fill up. Follow the manual on the procedure (engine off for 15 minutes, blah blah...)
Also, check the air in your tires, underinflation will cause poor gas mileage as the rolling resistance is increased.

In theory premium gas will give you better MPG's since you need less of it to get the same burn.

And most importantly, do not estimate your gas mileage by the fuel gauge. The only way to really estimate your MPG's is by following:

1. fill up your car until the pump automatically shuts off.
2. reset your trip odometer.
3. drive as you normally would
4. when gas light is on, go back to the same station same pump, preferrably at the same time of day (temperature/humidity should be about the same)
5. Fill up until auto shut off
6. note the gallons needed to fill the tank.
7. note the miles on the trip odometer
8. divide miles by the gallons
9. repeat steps 1 through 8 3-5 times
10. average the results.

[jerky]

you are still alittle on the low side with your mileage. some people have experienced better gas mileage as the car gets more miles. with the good stuff you will get less mileage than with 87. i used 91 (damn Cali) and i was consistently getting like 23 to 24 mpg and now with 87 i am getting 28 to 30 mpg. try switching back if you are concerned with gas mileage. if you want to "race" then use the high octane.

[sniperSI]

I've found in the 30,000 miles i've put on my EP a few things


#1 it's worth the extra for 93 octane because you make the differance up in better gas mileage.

#2 My 3rd (starting at 20,000 miles) always made a grinding noise, and now it's in the shop getting the syncros replaced for free by honda.

#3 After 4k 5k miles gas mileage starts going down fast w/o an oil change so change regularly.

that's my take on your issues. Sounds pretty common but can be fixed.

[sniperSI]

Originally posted by jerky
you are still alittle on the low side with your mileage. some people have experienced better gas mileage as the car gets more miles. with the good stuff you will get less mileage than with 87. i used 91 (damn Cali) and i was consistently getting like 23 to 24 mpg and now with 87 i am getting 28 to 30 mpg. try switching back if you are concerned with gas mileage. if you want to "race" then use the high octane.


Why would you get better mileage on lower octane gas, for argument sakes 87 octane makes less burn then 93.

I guess it's preferance but for my driving i get better mileage with 93 octane.

[Surprise]

Originally posted by jerky
with the good stuff you will get less mileage than with 87. i used 91 (damn Cali) and i was consistently getting like 23 to 24 mpg and now with 87 i am getting 28 to 30 mpg

My experience is the same, barely got 25 mpg with 91. But after going to 87 mileage went up to an average of 27.8 mpg.

Look to see the gas mileage other people have at this poll (http://ephatch.com/forum/showthread.php?threadid=16416) to see the gas mileage other people have

[jerky]

i don't know why it is like that, but that is what my car has been experiencing. when i first got my car i used 91 all the time, but then i noticed my gas mileage wasn't that great. i switched to 87 and i saw an immediate increase. now i just use 87.:)

[Surprise]

Originally posted by sniperSI



Why would you get better mileage on lower octane gas, for argument sakes 87 octane makes less burn then 93.

I guess it's preferance but for my driving i get better mileage with 93 octane.


Posted octane numbers on gasoline pumps are a result of testing fuel performance under laboratory and actual operating conditions. The higher the octane rating on fuel the less volatile (evaporative qualities) and the slower the fuel burns. Higher octane fuel contains more POTENTIAL energy but requires the higher heat generated by higher compression ratio engines to properly condition the fuel to RELEASE that higher potential energy. In the refining process, fewer gallons of higher octane fuels are yielded from a barrel of raw crude.
Quoted from:http://www.leeric.lsu.edu/bgbb/7/ecep/trans/b/b.htm

higher the octane rating on fuel the less volatile=less fuel economy when used in an engine not desighned for it (like ours, do to low compression ratio).

[shimmy_yaz]

David K. - Did they cover the syncros in the warranty as this seems to be a common problem. Have you had any problems since u had them replaced?

[sniperSI]

They covered mine and simone's

[Zero Three Si]

I seem to get shitty gas mileage if I set the cruise control at 70mph or above. I get like 260-280 a tank and the light comes on.

I know that when the light comes on...we still have 3 gallons of gas left.

It is true that if you have the windows closed and have the air on is more efficent after 40mph.
I read that in Men's Health.


How can you tell if you need new syncro's......I get grinding in 2nd,3rd and sometimes 4th gear....only every once in a great while though.

What exactly do the syncro's do???