tradesalot

I have a 93 Civic EX. I just bought the car a couple month's back. I got it with a blown engine. I bought a engine from a local salvage yard and got a 30 day warrenty. I had it swapped out and running in 3 days (working 12 days sucks when trying to work on cars). It runs great no smoke, codes or leaks. I figured since I had the warrenty I would run it hard until the warrenty was out so if anything was going to break it would then. Anyway I ran it up to about 5-6K alot and I got 38+ MPG in every tank (3 tanks full). Since then I have been taking it easy on the car and shifting around 3.5K or less. Now when i baby the car I get just barely over 30 MPG. (2 tanks 30.5 and 31.2). Am I missing something? I thought if you take it easy on a car you get better MPG.

So my questions are
Should I rev it up more to get better MPG?
Anyone else every have this happen?
Was it just a coensidence that is happened like this?

ej8123

the fuel injector cleaner....empty tank,,then pour some of that gas cleaner....

SiYouLater

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ej8123 &raquo;</TD></TR><TR><TD CLASS="quote">the fuel injector cleaner....empty tank,,then pour some of that gas cleaner....</TD></TR></TABLE>
wtf did you just say?

ej8123

i saiddd...try pourin some fuel injector cleaner ...that should help out the mpg

tradesalot

The injectors were cleaned before the engine was put in just a couple months ago.

SiYouLater

For the people that don't under stand, you said that when you drive the car hard you get 38mpg? But when driving normally you get lower?

tradesalot

correct. If I drive it hard I get better MPG.

fasthatchb18c1

Cars do have adaptive strategy so when start driving hard all the time the car will get used to it. When your long tem fuel trims change your gas mileage will go a little with it. The more you regularly beat on it the more your fuel trims change to either rich or lean. Just like if you buy a auto and slam the gas every time you hit the gas, after a while every time you hit the gas, even if its lightly, the car jumps forward thinking your going to slam the gas.

I dont know how many drive cycles you would have to drive normally to get back your old gas mileage but it will take a little.

You also have to take into consideration that you probably had brand new plugs and everything so a little wear and tear could be it as well or a combination of both. BTW that's what adaptive strategy is for, to compensate for wear

fasthatchb18c1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tradesalot &raquo;</TD></TR><TR><TD CLASS="quote">correct. If I drive it hard I get better MPG. </TD></TR></TABLE>

Wait ,what? ok forget it haha, that just doesn't make sense at all so ill leave this one alone.

tradesalot

I know it doesn't make since. I was just wondering if it had happened to anyone else or if this engine is a fluke or the first 3 tanks full was a fluke or????? I just thought it was alittle weird and thougth I would share what happened.

kuja396

No idea. But if it makes you feel better I've always gotten 30 mpg.. if i beat on it or drive slowly. Also doesn;t matter if im doing all highway or all city /shrug

SiYouLater

I get 35mpg on 90%fwy 10%city
I get 28-33mpg 70%fwy 30%city

tradesalot

Ok once again I ran it hard this time and got just under 38 mpg. So what the heck is going on?

EJAYATE

Don't complain about your magic gas. If you beat and get better mpg, then keep on beatin it.

BEYAAAH

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kuja396 &raquo;</TD></TR><TR><TD CLASS="quote">No idea. But if it makes you feel better I've always gotten 30 mpg.. if i beat on it or drive slowly. Also doesn;t matter if im doing all highway or all city /shrug</TD></TR></TABLE>

+1