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View Full Version : Who has done what to improve mileage?



StockGT92
02-16-2008, 03:53 AM
Sooo the inital 4 mpg gain after installing my header has averaged out between three tanks of gas (I drive a LOT, long commute to work) to around 2 mpg. While I am not complaining, I would like to pick all of your brains. I am getting 24 average mpg in mixed, but 75% highway, driving.

I refuse to putt around; my goal is still to be able to drive a touch on the aggressive side and gain a few more mpg. I typically cruise at 70 on the expressway and I don't want to go slower.
The car hardly ever sees more than 4000 RPM.

The only mods I have currently are a K&N air cleaner in the stock housing, and an eBay "Surewin" header with stock exhaust.

Short of an ECM flash or major engine surgery, what do you think? Has anyone experimented with changing cam timing to move the torque peak of the engine up or down?

juggernaut
02-16-2008, 04:16 AM
i have no personal experience with it, but i know that advancing your cam timing moves your power curve down to lower rpms. retarding it does the opposite. im not absolutely sure if this would work, but you could try advancing your cam timing to bring the powerband down, so you can run lower rpms, thus lower fuel consumption. but a bottle of fuel injector cleaner could possibly help. not that stuff you dump in your tank, that barely works. look for the stuff you hook up directly to your fuel line so the engine only runs off it. when the engine stalls, the can is empty and the job is done. not a drop of gasoline burned.

The Captain
02-16-2008, 04:27 AM
run your tire pressure 10% below max allowable pressure. While this may increase tire wear in the center of the tire, it will reduce rolling resistance. I run Nitrogen in my tires at 40psi. It doesn't get as hot and doesn't expand like air. I picked up a few MPG's. When I change to aggressive mode, I return it back to 34psi.

Murgatroy
02-16-2008, 06:23 AM
The easiest and most reliable way to increase your fuel economy is to change your driving style.

I know that is not what you want to hear, but it is the truth.

Keep your RPMs below 3k and you will see a serious increase.

Chaos gets 35mpg+ consistently, I am aware that a 4AFE is more economic than a 5SFE however. I run between 45 and 55mph max.

In Mudhoney, she was seeing 30mpg as well with the same driving habits.

A free flowing exhaust and intake tract as well as the tire inflation that John mentioned is great, but short of toning down your driving habits, you won't see a major increase in your economy.

VikingJZ
02-16-2008, 02:12 PM
Unless you learn to hypermile.

I'm still working at at that. I've been seeing returns about 28MPG since I messed with my throttle cables and began tweaking my driving. The SC EPA estimates when the car was released were 19 city and 22 hwy. Obviously I'm doing way better than that.


Actually, you might check into buying a new TOYOTA gas cap for the car. I'm dead serious about this. On my SC, I was getting like 15MPG. Lexus recommends that one replaces their gas cap (obviously with an OEM one) every ten years or 100,000 miles. What happens is that over time, the seal around the cap cracks and loses its pressure retaining abilities. After replacing it, I was getting 21. The results were immediate. I don't know what that will do to your car, but it won't hurt that's for sure.

alltracman78
02-17-2008, 01:15 AM
i have no personal experience with it, but i know that advancing your cam timing moves your power curve down to lower rpms. retarding it does the opposite.

Disregard, I wasn't paying attention.

celica9303
02-17-2008, 01:28 AM
Walk a lot or ride a bike lol sorry had to throw that out there. A cold air or short ram intake should help.

Blackcloud
02-17-2008, 01:28 AM
when i changed all fluids out (engine oil, tranny, transfer case, front and rear diffs) i gained 4mpg.

also depending on what setting i have my programmer at i gain mpg..

i get over 20mpg on the freeway

celicaGT90_05
02-17-2008, 05:42 AM
I've heard cold air intakes help with MPG but I didnt really notice anything on my ranger, it was just peppier. One thing you can do though is upgrade the ignition such as stronger coil, stronger, more efficient spark plugs, etc. It helps with a more complete combustion and therefore less wasted fuel. It may not be a drastic change though, I'm not sure what you would expect to see

Toy_Celi
02-17-2008, 09:38 PM
the key RPM is 2500, once you exceed, you take in more gas than really needed... its universal with all cars EXCEPT diesel because they redline around 1500.....

so dont cruise the 70mph, cruise in 2500rpm, you will see a difference....

Lonestag
02-17-2008, 09:49 PM
Keep your car well tuned.
Newer Spark Plugs, ect.
Get every once of weight you don't need out of the car.
I've heard that every 100lb = 1mpg, I don't know if thats true but lighter cars are easier to push, so there will be some effect.

Also, switching to synthetic oil (like mobile 1) will help a bit, less friction on the engine.

Really anything that reduces engine load will help. Underdrive pullys and a lightweight flywheel should help.

Now i'm in no way shape or form an expert, but as far as engine timing goes, I would reccomend advancing it a bit. You still are injecting the same amount of gas, but if your power is peaking higher up in the RPM's It seems to me that you would be getting more out of that gas.

Correct me if i'm wrong.

Also, they are expensive, but if your oxygen sensor isn't the greatest, that will rob a lot of milage.

I get about 33mpg in my 90 GT.

Hookecho
02-17-2008, 09:49 PM
I'm not 100% positive about this off the top of my head, but I'm pretty sure it's the opposite.
Advancing improves higher RPM power.

he has it right Jeremy. advance for lower rpm power and retard for higher.

StockGT92
02-18-2008, 12:42 PM
Thanks for all the tips, guys.
I am going to be doing my timing belt soon, and I just may try advancing the cam one "tooth." I figure, since I never really use the car's upper RPM range, why not? We will see how the computer reacts to that, though. I retarded the cam on a previous project (LT1 equipped '92 Camaro) in the name of not messing with the car too much; it made the Camaro's tiny little OBD1 brain go haywire.

I always thought that *increasing* tire pressure lowered rolling resistance? Correct me if I am wrong...

I am going to take the advice of the fluid change. I have a complete Royal Purple suit ready to go.. I'll do that before I the timing belt job, so as not to taint the results of the cam advance.

I have ran several different spark plugs in the car, but the ones that seem to work the best are Denso platinums. I have my parts store look up the ones for a '98 Camry with the dual electrode. Can't remember the number off the top of my head!

As far as getting weight out of the car, I think the most efficient way to do that would be for this 280 pound fatass to chill with the McMuffins. :yum:

extremeskillz
02-18-2008, 02:04 PM
when i changed all fluids out (engine oil, tranny, transfer case, front and rear diffs) i gained 4mpg.

also depending on what setting i have my programmer at i gain mpg..

i get over 20mpg on the freeway

Free up your intake and exhaust and you can gain up to 10 and 15 with your programmer. Ive seen it before and works awesome especially on diesels. Nice power increase as well.

19celica90
02-18-2008, 03:33 PM
to increase gas mileage i usually buy geo metros

hobbie2k
02-18-2008, 05:19 PM
The easiest way it to change your driving habits. My Cobalt rarely sees more than 3000rpm. I ususally shift at about 2500. Accelerate slowly, brake slowly, keep your speeds reasonable.

Next, keep your car well maintained. Good fluids, working sensors, etc.

Next thing is to keep your weight down, don't keep anything more in the car than you need. If you wanted to push it you could remove the rear seat, and a lot of the trunk lining. Maybe you could pull the AC if you don't use it. There is also some heavy sound deadening beneath a lot of the interior panels. Though some of these mods will reduce your daily useability. If you have some aftermarket wings or body kits, they could go as well, they're just weight and drag. Stick with lightweight wheels.

Finally, work on reducing your pumping losses through a good intake, manifold, header, high-flow cat, and exhaust. Just remember to keep your parts appropriate.

DarkSideCelica
02-18-2008, 10:11 PM
CAI has better power gains, but SRI gets better mpg...




i drive on the freeway at night a lot without my headlights up (i use my fogs only) and i gained 1.5 - 2 mpg ;)

StockGT92
02-19-2008, 02:21 PM
Well, I'm not too interested in taking weight out of the car. I like my A/C, my interior, and my system, so I'll just have to edit my driving habits. I never even gut my race cars.. I had a low-11 sec Camaro with a full interior, working A/C, and full stereo. Just my preference.
I may try to lower my expressway cruising speed to 65... that will still be safe (people drive like idiots around here) and maybe will net me an mpg or two.

As far as lowering pumping losses, I refuse to add a cold air because I don't want the noise. I already have a header, cat delete, with a stock resonator and muffler. That is staying too... I do not want my car to sound like a Civic Si with a fart can. I may try a 3 chamber flowmaster since I have one laying around.

Hypermilers get rear ended around here. Too many assholes driving. I have tried it in other cars, with some success, but it only is really practical on Sunday.

I am thinking seriously about this cam advance. The deal breaker is if it makes the car idle rough. We will see.. I will keep you all posted on any improvements from the Royal Purple. I'm doing that this weekend.

*edit* hey, do these programmers affect octane requirements?

Thanks guys!

juggernaut
02-19-2008, 07:15 PM
i dont think jumping a tooth on the cam gear will help you at all.. i did a t-belt on a volvo in school a couple months back, and i forget exactly how i figured this out, but i think that if i jumped a tooth on that volvo, it wouldve changed the cam timing by 9 degrees. 9 degrees is a lot man... i would say to shoot for 1-3 degrees.

Conrad_Turbo
02-19-2008, 08:41 PM
Give the car a tune up, remove any intake/exhaust restriction, check tire pressures, alignment and all that jazz. Install a vac. gauge and hook it up to the intake manifold. Then drive while maintaining as high vac. as possible. That'll do 99% of what you can do to get out of the car.

ciento44
02-19-2008, 10:45 PM
I averaged about 29mpg in mixed driving in my celica...

On the highway, i used to hit literally 35-36 on the highway when driving an entire tank at 75-80mph on I-70E.

Stock, ran like butthole, broken exhaust, short short ram intake, and even with the headlights up.

But a lot of it is how fast you accelerate. I probably shift at higher rpms than a lot of you, but you have to realize that the engine works less hard while in it's powerband, so it's easier to accelerate with less application of the gas pedal if you're in higher rpms, and it's also easier for the car to maintain speed. You aren't dumping a buttload of gas into the car at 20mph in 3rd gear to try to stay with traffic, and thinking you're getting good gas mileage by keeping your revs low. It doesn't work that way.

I usually apply quarter throttle, and just let it ride until 3400rpms or so, so when i shift, i'm just about right back into the meat of the powerband.

Of course, this doesn't work quite the same for turbo cars.

alltracman78
02-20-2008, 12:40 AM
he has it right Jeremy. advance for lower rpm power and retard for higher.

Yeah, I guess that is right, adjusted my post.

StockGT92
02-20-2008, 02:27 AM
All the tune up stuff is done, alignment is factory and dead on, tire pressures are kept at 35 and checked weekly. I am running 10W30 oil, I figure the 5W30 Royal Purple going in soon might have some small effect.

Vacuum gauge is an interesting idea. A 1972 Electra 225 that I owned years ago had an "econo-meter" built into the dash that was just that. If you kept it out of the red, it would sip the gas at 12 mpg all day long. Mash the throttle, watch the needle fly across the gauge, 6 mpg. Maybe I'll add one of those snazzy gauge pods and stick a vacuum gauge in it, then tell everyone it's for boost. LOL.

I do agree that lugging the engine is not a great idea; the car seems to get the best mileage for not just shifting around 3000 using light throttle.

I am going to look into some programmers too.

Blackcloud
02-20-2008, 03:01 AM
Free up your intake and exhaust and you can gain up to 10 and 15 with your programmer. Ive seen it before and works awesome especially on diesels. Nice power increase as well.

they are already about as free as then can get.. 4" turbo back straight pipe (no kitty, no muffler) and my intake sucks air straight from behind the headlights.


and doing that only gives you like 50hp. doing that on a diesel gives you more in lower egts then it does in the power dept.. only gives you like 50hp.

my programmer adds 260hp and 460ftlb tq

Blackcloud
02-20-2008, 03:04 AM
I do agree that lugging the engine is not a great idea; the car seems to get the best mileage for not just shifting around 3000 using light throttle.

I am going to look into some programmers too.


when i lug is when i smoke (see siggy) as we all know large amounts of black smoke is nothing but unburnt fuel blowing out the pipe.

do they even make a programmer for cars? maybe hypertech does but im not sure

ciento44
02-20-2008, 03:18 PM
when i lug is when i smoke (see siggy) as we all know large amounts of black smoke is nothing but unburnt fuel blowing out the pipe.

do they even make a programmer for cars? maybe hypertech does but im not sure

They make them for gas-powered trucks, so i don't see why cars would be that much different.

juggernaut
02-20-2008, 03:20 PM
there are plenty of programmers for cars, but none are for celicas. there could possibly be one out there for 2000+, but nothing for 4th 5th or 6th gens.

ciento44
02-20-2008, 03:45 PM
there are plenty of programmers for cars, but none are for celicas. there could possibly be one out there for 2000+, but nothing for 4th 5th or 6th gens.

Run megasquirt. If you mess with your fuel map to lean it out in the lower rpms, you could probably pick up some decent mpg at not much risk to the car.

I'm working on getting a chipped P28 ecu to work with the 5sfe, which will end up giving the same options, for less money than even megasquirt.

Blackcloud
02-20-2008, 11:57 PM
imo the hp gained/cost ratio of a chip on a gasser is not worth it

StockGT92
02-21-2008, 03:25 AM
Yeahhh it's looking like fooling with the ECM is going to be false economy. I'm just going to have to learn to keep my foot off the floor.. not easy with all the screaming horsepower waiting to be unleashed from the 2.2.

Hmm... I guess one can easily get a programmer for a Duramax... sooo... I'll just swap one in! Sweet. I heard there is a bolt-in kit for this swap.... Although, I do prefer the 7.3 Powerstroke. Decisions, decisions.

I did buy LT1 edit for my 200,000 mile Camaro, and a month of jiving around with the fuel curves on the laptop yielded about 40-50 extra miles per tank. And a little pinging here and there. ;)

wizzards581
02-21-2008, 08:11 PM
swap the ST 1.8L engine... or swap the tranny to the camry for longer gears.

StockGT92
02-22-2008, 01:54 AM
I have heard that the Camry 5 speeds are fairly rare to come across. I was working at Carmax a couple of years ago, and a 00 or 01 4 cyl. 5 speed Sport came through with only 40,000 miles. It was LOADED too, they wanted too much freaking money for it.

Besides, if I am going to do anything to my Celica, it's going to be a turbo, and it's going to be when the 5SFE gives up the ghost. At 75,000 miles currently, I think that will be a long time from now.

ciento44
02-22-2008, 03:44 PM
I have heard that the Camry 5 speeds are fairly rare to come across. I was working at Carmax a couple of years ago, and a 00 or 01 4 cyl. 5 speed Sport came through with only 40,000 miles. It was LOADED too, they wanted too much freaking money for it.

Besides, if I am going to do anything to my Celica, it's going to be a turbo, and it's going to be when the 5SFE gives up the ghost. At 75,000 miles currently, I think that will be a long time from now.

An E153 out of a 5-speed V6 camry or Solara would do, too...

Toy_Celi
02-25-2008, 07:52 PM
you might be able to see the Mpg increase with the 2500rpm.... my mom was cruising at 85mph and 2400rpm, it was pretty smooth.... windows up, newly rotated/filled tires, and a 3.5l V6 lol

theologygeek
02-25-2008, 10:48 PM
You do a lot of highway driving. Improve your aerodynamics. Drop the car 2 inches and add a more aerodynamic front bumper and a rear wing to break up the air flow at the back of the car. There is a reason NASCAR runs there cars only 1/2 from the ground.

I have Tein Coilovers so I can adjust my height. In fact I spent the morning working on raising the back 1/4 inch because I have a tire that rubs when I hit a bump.

I have only had my Celica for about 3 weeks so I don't know my MPG but I will post it when I fill up. I have used a little over half a tank (according to the dash gauge) and I have driven 215 miles. I am anxious to see the final numbers. they may be close to 30 MPG.

theologygeek
02-27-2008, 08:47 PM
I just filled up. I got 28.7MPG on my first tank.

I have to qualify that by saying I am driving the speed limit all of the time. Since I just got the car, I only have a permit in the front window - no plates. My car kind of sticks out (pictires coming soon). The first day I had it I was pulled over because of no plates.

I have no engine mods done at all yet: stock air filter, muffler, wires...All of the work done to my car was for show or handling purposes: body kid, TRD Wing, carbon scoop, carbon mirror covers, Alpine deck, Kicker Amp... Tein coilovers, 17 " wheels, rear sway bar...

jlspec
02-28-2008, 02:12 AM
You should be getting more then 24mpg on a 5S-FE motor. My all-trac with HKS SMF and Blitz catback I do about 20-22 MPG. You might want to do a complete tune-up and check your cat.

On my integra after replacing my bad axles I got an average of 3mpg gain. I was doing about 29-30 MPG before and now I constantly do 32-33 mpg.

geebes
02-28-2008, 02:27 AM
I can get up to 30's if I'm being real gentle with the 3sgte, the 5sfe I typically get 27-35

zmile06
02-28-2008, 03:05 AM
Ok first mod i ever did to my ST was the exhaust. 200 bucks to get a crimp bent high flowing exhaust was amazing.. I was like why is my car getting like 200 miles a fill up wtf. The exhaust was falling apart... The flex pipe was leaking and blah. So i replaced all that took out and restriction Down pipe back done in 2.25, got 100 more miles on a fill up. I was like WTF!!! Did an alignment got 30 more a fill up, or so. I get around 300 a fill up now with a really horrible alignment. I just swapped in a new engine... want to get some ebiach in there before i align it.

Best bet is getting a full exhaust done. I would honestly recommend mandrel bends... Because the celica's exhaust has a ton of bends in it. My exhaust is a lot louder then i like but i deal with it for MPG sake. Don't get a flow master muffler get magna flow or blitz.

Other then that synthetic oil will do wonders, just make sure u get the good stuff not wal mart special synthetic. And different cars like different synthetics.

Tune up like crazy close all leaks. U would save money just doing a good tune up. NGK plugs wires or OEM gas cap always works, OEM NOTHING ELSE.

Other then that check around and see what gas station is the most accurate not just cheapest... Some gas stations around here are off as much as 12 percent.

hemlocke
02-28-2008, 03:55 AM
Spend $19.99 (Autozone) and get yourself a front end (Back, too, if you have 4-wheel discs) brake hardware kit. 18 year old springs and sliders cause pads to drag. New hardware will allow the pads to slide easier, and the springs will help keep the pads off the rotors until they are engaged.

theologygeek
03-03-2008, 04:16 AM
Next thing is to keep your weight down..

Dude... everyone is on me about my weight. I like buritos, so what? It's a trade off; they add a little weight to the chassie but they help me regulate my air pressure.

supra97rx7
03-03-2008, 06:37 AM
The easiest and most reliable way to increase your fuel economy is to change your driving style.

I know that is not what you want to hear, but it is the truth.

Keep your RPMs below 3k and you will see a serious increase.

Chaos gets 35mpg+ consistently, I am aware that a 4AFE is more economic than a 5SFE however. I run between 45 and 55mph max.

In Mudhoney, she was seeing 30mpg as well with the same driving habits.

A free flowing exhaust and intake tract as well as the tire inflation that John mentioned is great, but short of toning down your driving habits, you won't see a major increase in your economy.

last tank, shifting as you say got me 210 miles on a tank. at the halfway mark i had just 100. granted, something is wrong with my car, but comparatively, i've been driving like a wannabe-racer, shifting at 4500 with a pretty heavy foot. i'm at half tank right now, with 140 miles. pretty weird.

there is one thing that i know of for certain that is messed up - the idle speed is pretty high. when it's warmed up and sits for maybe 20 seconds, it'll go down to 1000. tap the gas once (in neutral) and the idle will go back to 1800, and SLOWLY drop down, minimizing at 1000.

i'm guessing the reason why i'm getting better gas mileage shifting at 4500 isn't because of how i'm shifting, but because of my driving. i believe i've had more continous driving - not like all highway, but more greenlights, less stops.

i'm quite puzzled to say the least.
oh, and based on the numbers people are getting, my celica is also raping the wallet.

(misc. question - when computing mpg, are you using 15.9 or 12.9 gallons?)

G.W
03-03-2008, 04:49 PM
I had a 12.9 tank. I got my mpg by how many miles I traveled to gallons need to fill my tank.

It sounds like you need clean your intake.
1. clean intake
2. check vacuum lines
3. check tire pressure

VikingJZ
03-03-2008, 05:26 PM
Well....I can say that when I had my 1990 GT that I was averaging around 25 or 26 overall. My Lexus yields me about 24 or 25 depending on how I drive. Contrary to popular belief, I do stay out of it on daily driving. I even have yet to do a tune up on the car. Right now its running the ORIGINAL wires, cap, and rotor. The plugs are obviously newer but I have no idea when they were last done.

http://vids.myspace.com/index.cfm?fuseaction=vids.individual&VideoID=29365996

How to Hypermile.

Obviously that leaves a lot to be desired. You can get staunch increases with ANY car if you drive like a pansy...lol. But hey, if your car doesn't make big HP....make it make big MPG

Newbster
03-03-2008, 06:24 PM
On a different note, does anyone know how many gallons left the gas light comes on?

revv_head
03-04-2008, 10:01 AM
Remove your O2 sensor. You will get 5mpg+ more.

revv_head
03-04-2008, 10:14 AM
I'm not sure in miles per gallon but its like 8 Litres to 100km so like 22mpg? It is prob wrong but i get like 500km to a tank so like 310miles. I regularly redline but. The norm for me is at lights accelerate to 5400rpm shift into second then 4800rpm into third. Then drive normally from there. But then again i probably hit over 140km/h (85mph) most days though.