improving my mpg on my 95 pathy

[Coucoui6]

okay... i know there is alot of snake oil stuff out there... but i thought that i will post what have worked for me so far.

 

i have a pretty stock 95 pathy with a poor man's lift and 31" timberland tires. my intake has six 2" holes drilled in my air filter box (before the filter) and i have aftermarket muffler weld in place. these are all my performance mods... no more.

 

problems that may affect my MPG: i have alot of small exhaust leaks with my exhaust system held up by hose clamps. my cat is abit rusty to the point the metal sheld is loose but i still pass Cali smog without problem.

 

okay here is what i did to increase my MPG.

i made sure my tires are pumped to max. manufacture psi: 40 psi for my tires.

i am drive more conservatively now... ie. trying to accelerated slower and keep my rpm under 3K .

once my truck is moving i try to keep my rpm to under 2.5K rpm.

i mix 3oz of acetone and 3 oz of xylene per 10 gals of gas.

i made a fuel heater with 5/8th copper tubing. i took 3' of tubing wrap it into a small coil and placed it over my top radiator tube. and then routed the fuel line from the fuel filter to the copper tubing and back to the rail.

 

so far i am happy to report i've been averaging 17.5 MPG on all city driving and 18.7 MPG with a mix of highway/city.

 

i've now did a tune up... by replacing my ignition parts. i have 135K miles with factory original stuff. New OEM spark plug cap and rotor cap, i use Brisk Racing LSG performance plugs ( not the LSG Brisk halo plugs) but my plugs was expensive... about $15 per plug with shipping. it was recommended by another site that i read and liked. i am also using nology hotwires. now the nology was alot.... i got the purple ones from nopi.com because it was $218 rather $238. plus i had a $20 coupon.

 

i only used the nology because it was the only performance wire with factory specific plug ends. all the other low Ohm wires was generic and not specific. i am now driving my 1st tank of gas with my new parts and without acetone/xylene. i will provide feed back later.

 

thanks,

coucoui 6

Edited August 31, 2008 by Coucoui6

[MY1PATH]

with over 300 invested in Ignition parts I bet you still can't get better mpg than a set of $300 headers, I get somwhere arround 20MPG on the higway in my 89 and I run $4 NGK V-power plugs and $80 taylor wires. on the otherhand, installation can prove costly or time consuming compared to ignition upgrades.

[Coucoui6]

if you read any of the forum focused on MPG... headers and exhaust upgrades are not of concern... why... because if your driving for fuel efficiency... you will never be at WOT thus stock exhaust pipe will do just fine...

 

i know header give you horse power but horse power take more gas. the ignition system can provide a better burn... but yes. alot of after market ignition stuff is just snake oil... but i guess i was reading more of the positive rather than negitives for MPG.

 

FYI... alot of the MPG forums actually suggects hot air intake rather than cool... and to block the radiator. why??? to allow the motor to run hotter. your ecu will taper off the fuel.

 

coucoui 6

[SC88Pathy]

i know header give you horse power but horse power take more gas. the ignition system can provide a better burn... but yes. alot of after market ignition stuff is just snake oil... but i guess i was reading more of the positive rather than negitives for MPG.

 

BZZZT! Wrong!

 

With headers you're producing more HP with the SAME amount of gas. Headers only affect exhaust gasses, they have no effect on the intake. More HP + Same amount of gas = Better MPG Of course the type of people who get headers are more likely to be the type to floor it...

 

Mods that do change the amount of fuel you use would include: hotter cams, forced induction (SC or Turbo variety), ECU remapping (depending on how it is remapped), etc

 

Also to give you an idea of just how much your mods have "improved" your fuel mileage I get 16.5mpg in my bone stock 88 with a mix of rural mountain roads and freeway. Oh and I drive like a bat out of hell, redline is my friend.

Edited August 30, 2008 by SC88Pathy

[MY1PATH]

With headers you're producing more HP with the SAME amount of gas. Headers only affect exhaust gasses, they have no effect on the intake. More HP + Same amount of gas = Better MPG Of course the type of people who get headers are more likely to be the type to floor it...

 

After headers my MPG while driving conservatively Improved! With the headers Installed I do not have to push the gass in as far to maintain the same speeds as before and that Is the only reason I can think of to explain how I picked up an extra 2-3 MPG on the highway. I have several friends all with differant vehicles that have installed headers and noticed similar results when driving conservatively.

[88pathoffroad]

Ditto...headers can increase MPG's. Why the hot fuel? I've never heard of anyone trying that.

[Coucoui6]

BZZZT! Wrong!

 

With headers you're producing more HP with the SAME amount of gas. Headers only affect exhaust gasses, they have no effect on the intake. More HP + Same amount of gas = Better MPG Of course the type of people who get headers are more likely to be the type to floor it...

 

Mods that do change the amount of fuel you use would include: hotter cams, forced induction (SC or Turbo variety), ECU remapping (depending on how it is remapped), etc

 

Also to give you an idea of just how much your mods have "improved" your fuel mileage I get 16.5mpg in my bone stock 88 with a mix of rural mountain roads and freeway. Oh and I drive like a bat out of hell, redline is my friend.

 

 

ofcourse that your bone stock pathy will give you better thank mine. if you have bone stock wheel size also...

i posted that i got 14.5 mpg prior to my mpg mods and alter driving habbits... i now get 17.5 all city and i'm able to better your 16.5 with highway mix... and stock wheel size...

 

that is real gains.... i'm not just posting crap info...

 

 

as far as headers...i do under stand that it is only exhaust.... and for the most part will not affect air intake or fuel. but please bear with me and my example. the motor can be viewed as one big air pump. the faster you allow it to intake air the faster it will expel it.... but the opposite can take place ... the faster the air is expelled the more your intake can take in air thus trigger MAS and ECU to give more fuel.

 

nothing is free with horse power... it take more air, spark and fuel period!

Edited August 31, 2008 by Coucoui6

[Coucoui6]

Ditto...headers can increase MPG's. Why the hot fuel? I've never heard of anyone trying that.

 

 

i picked up these tip on all the different forums that focus on MPG... some info was crap but some came from good sites. the fuel heater is to make the gas more volitile and expand... gas is denser when cold just like air.

 

now i also read but will not do is radiator block and hot air intake. the thought is to increase the operating temp of your motor so the ecu will inject less fuel.

 

other mods include modifing the O2 signal to be rich with EFIE units.

[Coucoui6]

FYI to all that is reading this tread... i know the focus is on forum is pathy and offroad with HP mods or suspension mods. i really dont what to debate anyone on concept or thories. i just thought i would post info that is helping me with my new focus, MPG efficiency. i just hope to help others if they want this info. prior to my tread... i searched and no real info was on this forums.

 

if anyone who reads my posted info and don't think it will work or don't want to try it. that is okay but please don't be pestimistic and post snake oil comments.

 

i'm in experimental mode. ie. i'm not sure if my new brisk racing plugs will work. i just found another guy with a 4 cyl. sidekick... i really liked his page and he was able to document improvement with the brisk racing lgs plugs with the use of Granatelli's MPG/Plus Performance Ignition Set. (and no he is not selling anything or sponsored)

 

 

once again i only used nology hotwire because granatelli did not make wires with oem type end connectors for our pathy.

i will post my results after a few full tanks of gas... i have a gas/MPG log in my car.

 

so here is my final thought on header or intake mods for fuel efficiency. there is alot of performance shops here in my area advertising these thing for gas savings......

 

the biggest savings is driving behavior. if you drive conservatively ie. keeping the rpm low and slow acceleration and slow decceleration. the modified intake and exhaust will not help. factory pipes is more than adequate for these condition.

Edited August 31, 2008 by Coucoui6

[Coucoui6]

additional thought.... things that is definitely hurting my MPG...

1. my big tires. with spare.

2. my spare rear rack... more weight.

3. my c channel front bumper. poor air dynamics and heavy.

4. my air box alterations. it triggers the MAS.

5. my exhaust leaks could be a factor.

6. my 3" lift. push more air on the road.

 

if the above items was not their i think i maybe able to get closer to 20 mpg on city driving!

fyi. please look at www.fueleconomy.gov for some good info. as for other forums just do a google search... there is a bunch... with topic like hypermiliing or www.metrompg.com

[Legalalien]

Thanks for the info. The most notisiable gas inproving mod I have made is to install Bosch dual electrode sparkplugs My pathy went form 11 MPG to 17MPG city by just doing that change. I just installed headers and havent noticed a great deal of improvment on the mpg but I have noticed better hi end power, the tranny doesn't down shift as often and it will keep speed going uphill without having to give it more gas. Next mod will be a better flowing muffler and larger sise pipes, we will see how it works. but thanks again for the info, every little bit helps.

[SC88Pathy]

ofcourse that your bone stock pathy will give you better thank mine. if you have bone stock wheel size also...

i posted that i got 14.5 mpg prior to my mpg mods and alter driving habbits... i now get 17.5 all city and i'm able to better your 16.5 with highway mix... and stock wheel size...

 

Take a look at my sig, I'm also running 31's.

 

I'm not saying what you're posting is crap, just that the gains aren't that impressive considering the amount of money you're investing. I see similar fluctuations in mpg do to seasonal changes.

 

Also worrying about the aerodynamics of an aftermarket bumper on these vehicles is kind of silly. They have the aerodynamics of a brick, your bumper is not going to change that. Worrying about the "extra" weight of the external spare is also kind of silly. Instead of having a 4000 pound truck you'll have a 3950 pound truck. Now if you remove the spare carrier, remove the passenger seats, switch to fiberglass fenders, remove all of the internal sound deadening, and have a fiberglass or carbon fiber hood built then you'll probably notice a difference.

 

Another little talked about tid-bit. Most engines in the real world are at their most efficient (i.e. best HP to fuel use ratio) at about 75% throttle. (Theoretically engines would be at their most efficient at WOT but it doesn't work in real life due to friction and other constraints) (also I got this fact from Road and Track's technical section several years ago, sorry I don't remember the exact volume no.)

[Coucoui6]

sc88pathy,

 

my 14.5 to 17.5 city driving is a big gain. now if you are using 31" wheels and your doing 16.5 for both highway and city type driving that is what the new CAFE rating is for our pathy ... check out www.fuelefficiency.gov. i will say your are doing a bit better than the new ratings because of your tires are big. two thought on big wheels... if you are driving hwy the big wheel can save you gas... it like having another hwy gear. but if you are doing all city... it will hurt your MPG alot! big difference.

 

so i did one tank of gas 2 weeks ago with about 150 miles of highway and the rest city. during this tank of gas i had other passengers and alot of AC use.... my mpg mods was only my fuel heater, acetone and xylene... I am happy to report 18.5 MPG... with mix use. these numbers seems small but it is really big improvements.

 

ie. my city number from 14.5 to 17.5 is 20% improvement is MPG and on a 20 gal tank of gas. this 20% improvement will give me an additional 60 miles of driving. that is big! once again, i'm posting real world info.

 

i see your live in Santa Cruz. your will have a bigger temp range from season to season... is temp will affect MPG... ie. cooler the motor the more gas it uses. as far as weight ... for every 100 lbs of savings can equate to 1-2% MPG gain! and my Channel bumper is heavy! as for you other comment on 75% throttle for HP and fuel use ... i think that is correct for power stand point. but Max MPG no.

 

now i'm not perfect with my driving but driving for max MPG, you will try to use min. fuel as possible to sustain a save and reasonable travel speeds. so for the 95% of socal drivers that means driving like your 95 years old! your throttle should never get past 50%.

 

as for automakers ... 14.7% is the stochiometer for your fuel to air ratio... that is too much... you know we can lean our cars out more and get good emissions with better MPG. other countries dont all have this same fuel:air ratio.

Edited September 1, 2008 by Coucoui6