Better Fuel Economy
 

Hi All,

I was wondering if anyone has any ideas on how I can increase the fuel efficiency of my 1999 accent. Its already pretty good but I'm curious if I can make it even better.

I was thinking that maybe a K&N air filter and some new injectors might help.

Thanks.

the air filter and injectors will do nothing. weather the filters flow better is besides the point - when worried about FE you are keeping your rpm's low so the biggest restriction is the throttle plate in the throttle body.

as for injectors, why? something wrong with yours? if not leave them alone. injector cleaners are useless these days because all modern fuels are much cleaner and already have a good load of detergents in them.

stay away from snake oils and fuel 'catalysts' etc.

now things that do work: increase tire pressure a bit. just don't go to the max pressure on the tire sidewall. i run about 40 psi myself.

change trans fluid. is it an auto or manual? more options with a manual for FE.

remove unnecessary weight

a block heater is a good idea. the computer can't trust the sensors when the engine is cold so it goes into 'open loop' and tosses a lot of fuel at it for safety. the quicker its warm the quicker all systems function fully.

mostly modify your driving habits. coast in neutral when you can. for example, getting off the highway on a ramp. why power down it and then waste that energy in brakes? just cost it. same when coming to a stoplight or stop sign.

above all i'd join some hypermiling forums. i like gassavers.org myself as i find them to have the most accurate info and they look for evidence of claims not just 'buddy says it works' crap you see a lot.

Thanks for the tips... The car is an Automatic. So if changing the is a good idea will using a synthetic one help more ?

Synthetic oil will not give you better MPG, but it will last longer. The problem is that it still gets dirty.

A clean air filter does help, also a new fuel filter is always a good idea if you're not sure about yours.

Check the tension of the timing belt, make sure it's in good condition and adjusted correctly. It's a simple job really.

If you don't know about the status of the spark plugs, it's a good idea to pull one and look at it.

Tire pressure really works, I buy tires that are spec to 51 psi, and fill them up accordingly.

Coasting a lot, and being easy on the gas works great. Stay under speed limits. Avoid situations where you need to use the brakes. Keep a long clear distance to the next car. Stay in the slow lane. If you can draft off a big truck, you save big MPGs there.

Plan to combine trips. Plan your driving to avoid stopping at traffic lights.

just be REALLY careful drafting a big truck! it can be dangerous and its illegal!

good call on the plugs, just bought myself some new ones last night. hopefully install them this weekend...just got the coppers, no point in platinums in these cars and i'm rather skeptical on weather or not irridums do anything. plus they're ungodly expensive.

synthetic in the crankcase doesn't do much except extend your oil change interval but i have a suspicion that it would be more helpful in the gearbox as it doesn't get as dirty there. i noticed a large difference when i drained my manual trans and filled with synthetic.

TrueDelta conducts a real-world gas mileage survey that, unlike others, includes information on driving style and driving conditions. Results so far for the Accent here:

Real-world Hyundai Accent gas mileage

Only 2002 and newer so far, but we'll be adding powertrain data to support earlier years.

repair manual?
 

My 99 Accent now has 105,000 miles and it's still running great! My FE averages about 30-35 mpg. If I'm on a long driving trip, I'll get 35-37, and 3 times I've had a tank of gas that went 40 mpg.

I like the idea of putting synthetic in my transmission and just might do that next week. I would love to find a repair manual for this car. Does anyone know where to get one?

http://www.hmaservice.com/

best of all its free;) but of a bastard to navigate but its got all the info. use IE, it doesnt like firefox much.

changing the trans oil is very easy. hyundai designed their cars with service in mind - unlike a few other manufacturers i could name.

make sure you're on level ground. remove the fill plug FIRST. you dont want to find it completely seized after you drain the trans. get your oil pan ready. big bolt on the bottom of the trans for draining, its actually on the bolting flange of the trans. drain into a pan. put the drain plug back. i like to use a very small amount of anti-seize lubricant on the threads to ensure you never get seizing. find a good length of tubing that fits into the fill plug and just pour the new gear oil down the tube until it just starts to overflow. let the excess drain off and cap the fill plug. done.

follow these directions with the manuals/pictures and its really dead easy. removing the battery will give you more room to work btw.