More specifically, the d16 zc..

I've heard that accelerating rapidly to your speed, then putting in a high gear to maintain is best.. but I've always been one to shift as early as possible.

I know that big v8's like to rev low, and tiny 4bangers such as hondas like to rev high, but where is the efficiency best for these cars?

Matt

 

If your wanting to know when to shift on a motor just take a look at the at the its factory spec's like peak tq and hp or get it dynoed, then take in to fact your gearing and try shift at a place thats closest to not pushing your current gear out of the power band but will also put you next gear into the power band when you shift. Trying this on a civic cx or vx wont happen haha

 

So your saying shift in the factory torque band?? Because I normally shift the second I feel it has enough power to do so.. usually around 2-2300 rpm's tops. Unless i'm trying to pick up speed quick

 

well when racing, yes. A few hundred below the stock redline would do

 

no man, for maximum efficiency!!

 

oops, forget powerbands then. Its mostly about vacuum and load, theres a theory behind this in a thread somewhere on here. That goes somewhat like this: your better off on a given grade to up it in a lower gear at higher rpm then a higher gear at lower rpm because of the extra load seen by the map and the fuel it would to compensate would be more. Effeciency gets complicated haha

 

interesting. what else do you know?

 

I really cant remember, i've read through threads on here. Search efficiency and im sure youll find it

 

will do! thank you!

 

so what are some common shift points for you guys who get phenominal gas mileage in their Hondas?

 

i get 42 and typically shift as soon as my car can go to the next gear without bogging. and i take forever to get up to speed. sometimes on down hills i will shift 1-3-5 or 2-4-5

 

Thats what I do.. as soon as the car can take the next gear I change.
What car/motor gets 42 mpg? Is that city or higway?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by davefromPA &raquo;</TD></TR><TR><TD CLASS="quote">i get 42 and typically shift as soon as my car can go to the next gear without bogging. and i take forever to get up to speed. sometimes on down hills i will shift 1-3-5 or 2-4-5</TD></TR></TABLE>

sounds about right...i get around 38 mpg highway when i shift about 3k-4k. i also hit vtec about 5-15 times on a tank. depends on how many stupid drivers are on the road. lol

and btw its a stock d16y8

 

thats a stock 94 cx hatch with a dx engine/trans combo. with the cx engine is was getting 45-low 50's. im driving a good mix of city and highway. i stay at 60-65 highway and city is city.

 

slo hatch- what do you get in the city?

dave- thats crazy man lol. Damn I love hondas gas mileage!

I just hope my d16 zc gets good gas mileage. I love the motor so far.. it's so crisp and responsive.

 

engines are most efficient when they're drawing a lot of vacuum. hook up a vacuum gauge and keep it at as much vacuum as possible. they did this on some of the pontiacs in the 70s and called it an efficacy gauge.

 

DCSport, nice bit of info.. didnt know that. sounds like a simple install?

 

yep, im gonna do one soon. when i get money lol. college is expensive (so much i have to move back in with my parent, gag). im taking automotive (2 year degree) and the Honda PACT program. learning a lot more than i ever thought.

 

That is deffinently pretty interesting.

I have a wideband hooked up which helps..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 85_305 &raquo;</TD></TR><TR><TD CLASS="quote">slo hatch- what do you get in the city?

dave- thats crazy man lol. Damn I love hondas gas mileage!

I just hope my d16 zc gets good gas mileage. I love the motor so far.. it's so crisp and responsive.</TD></TR></TABLE>

i really couldnt tell you...i think on one tank i can get like 32 city but that is practically ALL city...i get in the mood to either drive interstate most of the time or just city/rural driving the rest. lol

 

32mpg city is awesome.

how do these damn cars get such great mileage??

 

lol because they produce next to no power at all.

 

Generally, the EG chassis Civic always got better gas mileage than the EK chassis. This is due to the different in engine sizes and vehicle weights. The EK was heavier than the EG chassis. Also, the hatches would get better gas mileage than the coupe, and then coupe better than the sedan. Obviously this was also due to weight. Just like DCSportEJ1Civic said, the D-series motors don't make a ton of power, but they are a very efficient and well running motor stock. I know my girlfriend's 97 DX coupe manual gets 40 MPG peak and usually averages 37 MPG between city and highway driving. I've actually seen the EG hatch get 50 MPG peak before, but that was because it was a base model manual.

As far as optimum shift points, it kind of varies. In my RX-7 it's best efficiency was running down the interstate at 70 MPH pushing 3500 RPM's. A lot of people say the lower the RPM the better the gas mileage, but this is generally only true for V6 or V8 configurations that have torque to move the car at low RPM's. 4 cylinder cars usually like seeing slightly higher RPM's where they see an increase in efficiency.

 

Thanks for the info guys!!

I know v8's like turning lower rpm's and 4's like higher.. but damn, 3500?? Thats crazy.

I dont know. All I know is they have some secret to their gas mileage and i like it!

Oh and this d16 zc is actually pretty damn quick!

 

Yea, if you think the Honda 4 cylinder motors liked high RPM's, wait until you drive a rotary. lol Seen quite a few that will make peak power all the way up to 10,000 RPM's, pretty insane. Even crazier thing is that since you have no valve train, there's no worries of breaking a valve spring or floating the valves.