Turbotype

and I have some questions about it....First off, it's the D16y5, which is the econ vtec motor...I'm looking for ideas on what I can do to maximize my MPG...I already plan on changing the plugs to the 4 prong and K&N drop in filter...Thoughts?

fv8s

you can possibly get a tune for better mileage, but besides that just basic maintenence will improve your gas mileage

NOFX

There are some really great forums out there that go over tons of ways to save gas.

A big thing is just in the way you drive it of course.

Try GasSavers.org.

Turbotype

Is there anythin specific for the y5 that would benefit it outside of he general things?

Former User

Do an ignition system tune up, as already mentioned, and also clean the carbon out of the EGR valve and the ports and passages of the EGR chamber.

Turbotype

Carb cleaner would be sufficient to clean the EGR ports right?

Former User

Yes, with some vigorous scraping.

Turbotype

Like wirebrush scraping? haha...

Former User

Yes. Or any other tool that allows you to access and remove carbon build up without damaging the chamber, IM, or valve.

94EG8

If you were thinking about Bosch plugs they work like crap in a Honda. The cheap plain old NGKs will run better than just about anything else.

Meister vtec

as 94eg8 already stated the bosch +4 plugs suck ***,your best bet indeed is NGK.

the only things you can really do is run your car with a weight reduction,skinnier and/or lighter wheel combo (if there is any),maintenance,better breathing intake system, a tune with a lean afr for partial throttle,

all that with added with a smart driver could easily add another 4-5mpg to the goverment tested figures.

NOFX

I have managed to get 42mpg highway with my '98 EX (D16Y8) just by having it in good shape and driving smart.

BlackDeuceCoupe

Yep!

I gotta be the mileage king. I used to get 45-52 MPG with the HX motor. I'm still getting 39-42 MPG in the Si motor...

Driving smart is the largest part of it. Basically, that amounts to keeping your foot out of it (unless you're racing someone), coasting in neutral (on downhills), and don't lug around any extra weight (in the trunk).

Also, I use a K&N panel filter, mix acetone with my fuel (2 ounces per 10 gallons), run copper core plugs, 10W30 Mobil HM (high mileage) motor oil, Red Line MT-90 tranny fluid, and keep my (Pirelli P4) tires pumped up to 40-45 psi.

That's about the size of it.

NOFX

I've gotten that 42mpg while averaging 80mph. Seems a lot of cars have a sweet spot for mileage aroudn 70-80mph. At least that's in my experience.

Turbotype

I'd like to get 40mpg if possible...I shift at 3k rpms and coast when I can and haven't ever floored it lol, seems unnecessary considering its 115hp haha...I ordered a K&N drop in, which should be here today or tomorrow, changed the spark plugs, and am gonna clean out the EGR area this weekend...I don't know what oil type is has right now, but I think its 5W-30...Is there an advantage to going with the HM oil? Car is 126k on it...I think tire pressures are at 35-38...I guess I could goose them up a tad next fill up haha...

Thanks guys for the posts

smetrick

I get anywhere from 380-430 miles per tank of gas on my '99 HX with 5spd (about 37 to 41 mpg). I do some stop and go but generally a ten mile commute with half of it on a freeway. Driving habits, inflated tires, and whether or not it's summer are the biggest and cheapest influences on mpg. Someone told me summer blended gas has more BTUs in it.

BlackDeuceCoupe

Mobil 1 HM has the proper additive package to protect our motors.

Regular Mobil 1 has been reformulated to protect emission equipment in 2006 and newer cars.

If you run regular Mobil 1 in '92-'00 Vics, it will eventually wreck your engine, because most of the additives have been removed.

If you run Mobil 1 HM in '06 and newer Vics, it will wreck your emissions equipment, e.g. kill your cat, et cetera.

Newer motors are designed to run on neutered motor oil. Older motors are designed to run on (so called) HM motor oil.

That's basically the difference...

Turbotype

Gotcha, i'll make the switch at the next oil change

Ron454321

By newer motors do you mean lower milage? I have a 92 CX with a ZC swap that has about 50,000 miles. Any reason to use HM in there? I've always just used regular oil.

Turbotype

What about a hi-flow cat and a lighten flywheel? Would those help fuel economy? What about an intake system over the stock box?

94EG8

HXs are very picky about what you use for a cat, stick with the stock one. lightened flywheel probably wont make much difference either way. If you're going with a short ram you will loose low end power, if its a cold air intake you see minimal gains.

BlackDeuceCoupe

By 'newer', I meant 'newer' than 2006, e.g. 2006-2011 model years.

And, yes, you should be using HM motor oil, regardless of how many miles you have on your engine. It all about the additive package...

Here's a long post where I explain the whole situation ad naseum: https://honda-tech.com/forums/showpo...3&postcount=11

Matter of fact, I'll just repost it here, to save you some clicking...

Agreed!

I've used Mobil 1 10W-30 motor oil for years (Red Line MT-90 in my trannies) - and never had an engine/tranny failure!

The thing is...

Mobil 1 has been reformulated several times - and these reformulation(s) have involved protecting emissions equipment - often to the detriment of engine life!

Motor oil (these days) is designed to protect sensitive emissions equipment and increase fuel economy. Engine life has become secondary to oil conservation and clean air!

For instance: Mobil 1 was great in the late 90's, but the 'anti-wear additives' were wrecking cat converters - so, they removed a lot of the zinc, which acts as an extreme pressure (EP) additive. When they removed the zinc, top-fuel race cars started blowing rods and cranks like crazy - every race.

Mobil started adding (an existing) gearbox EP additive to Mobil 1, especially formulated for race cars - and a year later started putting the EP additive in regular Mobil 1. They call this additive "SuperSyn" and it's unique to Mobil 1.

Extra credit reading: http://findarticles.com/p/articles/m...7/ai_85494225/ (BNET Business Library - 2002 SuperSyn Article)

Today, ALL motor oil producers are required (by mandate) to take the 'anti-wear additives' out of regular motor oil, to protect 2006-up emissions equipment - and this ILSAC GF-4 oil is bad for older cars like ours!

Thankfully, Mobil 1 still makes oil designed for older rides. It's called "Mobil 1 High Mileage" - and it has all the 'anti-wear additives' that our rides require, plus the additive package contains chemistry that keeps the internals clean, and stop oil seepage, et cetera.

What do I run??? Mobil 1 High Mileage 10W-30 (and Purolator PureONE oil filters).

If you care about making your motor last DO NOT put ILSAC GF-4 (such as regular Mobil 1 motor oil) in it.

How can you tell the difference between regular Mobil 1 motor oil and M-1 HM???

Ron454321

Interesting information, thank you very much.

I was going to seafoam the cranckcase soon and obviously change oil thereafter. Now I know that I will be using HM to replace the regualr oil in there now.

However, do you recommend using a blend first before I switch to synthetic? Never done the switch before, my subie was already running synthetic.

BlackDeuceCoupe

No, you don't have to run a blend -- or flush out the old oil, et cetera.

The problem is when you switch from one brand of synthetic oil to another. Everyone uses different chemistry. In that case, you would want to switch to dino oil for one change. Then, use the new synthetic after the next drain.

Put another way, you DO NOT want to mix different brands of synthetic oil together...