The better car?

[willie@eco]

Hi guys, long time lurker/partial ecomodder. I currently drive a 92 Ford Festiva GL Sport, 5 speed, air con, no power steering ect. Now I drive 98% city and that 2% HWY. That 2% HWY is usually to the Walmart run because I cant stand the local Walmart. Ive noticed that hypermiling this little car i got the very best of 39.5 mpg. But driving around town and driving normal (not flooring it or anything) I'm getting a consistent 28 mpg. My question is, I've been considering a Civic VX or a Civic HX. I see all the time people say, 40 mpg normal city driving all the time. Is this really true? I know my Festiva weighs 1700 lbs but I also know about the vtec-e engines which improve economy. Should i look at selling my Festiva to buy a VX or HX? If so which of the 2 is better? I like the practicality of hatchbacks which is why I own a Festiva so not really into the coupe HX but if the real world mpg is that much better I would do it. Also, why is it that in normal driving I cant crack 30 mpg? Car has 72k original miles, new plugs, stock 12 inch alloys with 45psi inflated tires, top and bottom grill blocks, and i hardly ever pass 2,500 rpm.... You guys are the experts so I want to hear what you guys say. Thanks in advanced and hope to hear from ya soon!

[Ecky]

The main advantages of the VX and HX are that they have lean burn and tall gearing, which help a ton on the highway. Most Hondas with small engines can get 40+ in town, but these are 50+ or even 60+ cars on the highway.

To figure out why you can't get better economy, you need to consider where all of that energy is going. When you're rolling down the road, your engine can convert gasoline into usable mechanical energy at a certain efficiency, and the rest is lost as heat. Your drivetrain will turn a certain amount into heat as friction. Your brakes will turn some into heat as friction. Your tires will turn some into heat. Air resistance will turn forward motion into kinetic energy in the form of turbulence.

Mostly, you can get your economy up by reducing tire drag (low rolling resistance, high pressure), improving aero for highway speed driving (grille block, belly pan), reduce weight for city driving (takes less energy to get it up to speed, which you'll eventually waste in the form of heat in your brakes), and consider your routes very carefully so you're not having to accelerate and brake a lot.

Extended idling also takes its toll.

[willie@eco]

Ah, I see. My thing is, i hardly ever do HWY driving. Once a month maybe. Whats silly is, on the festiva forums guys are saying they get 30 mpg in their 1.8 dohc swap and im running a measly 1.3 with relatively low miles and cant crack 30 mpg. Car runs great, tight as a drum, like a top, and still even with easy driving 28 mpg is all i get. With engine off coasting and such and I can get passed the 30 mpg but why is it that others dont have to go to that extent and still get better mpg than me? I owened a 92 civic LX that was stock but had an HX trans and i think it was horrible. I did all city driving with it and could only manage 18 mpg with it. Tune up was fresh, o2 sensors ect. I think its the fact that my drive to work is 10 mins and back. So the car doesnt warm up enough and still runs in closed loop. Now I have also considered the fact that maybe vtec-e wont help me either because vtec-e engines need to warm up before running into lean mode from what i remember. Im in a bit of a pickle here...

[willie@eco]

Btw, I calculate my mpg by how many miles driven divided by the galons it took to fill the tank up. No gadgetry here to tell instant mpg. That imho is what i consider real world mpg.

[RedDevil]

10 minute trips in the city!
That's what my I10 does too, in the hands of my caring but not very ecodriving minded wife.
Anything beyond 30 mpg is sheer utopia.

[jakobnev]

Seems that the problem is the short trips, not the car.


Is it carburated?

[ThermionicScott]

Originally Posted by jakobnev

Seems that the problem is the short trips, not the car.

+1!

willie, do you have a block heater for your car? Having one of those warm up your engine every morning might help a lot with those short trips.

P.S. This may not be super-relevant, but what oil viscosity are you using? You may be able to get away with something that is thinner than spec just because you're almost never getting it up to operating temperature anyway.

[willie@eco]

Originally Posted by jakobnev

Seems that the problem is the short trips, not the car.


Is it carburated?

Fuel injection. And yes i think that might be my issue...

[willie@eco]

Originally Posted by ThermionicScott

+1!

willie, do you have a block heater for your car? Having one of those warm up your engine every morning might help a lot with those short trips.

P.S. This may not be super-relevant, but what oil viscosity are you using? You may be able to get away with something that is thinner than spec just because you're almost never getting it up to operating temperature anyway.

Hmmm.. interesting idea. Haven't thought about a block heater... hmm... and 10w-40. I think that is too thick as well now that you mentioned that. What shouod I run? 0w-20?

[ThermionicScott]

10W40, oh god.

I did a little Googling, and 5W30 is what Ford recommended for your car: http://www.revbase.com/BBBMotor/TSb/...adPdf?id=44867

Since you say the car is still in really good running shape, I'd put in something no thicker than 5W30 at the next change, and maybe even thinner. (My Subaru manual calls for 5W30 and I use 0W30 for its better flow at cold temperatures.)