Regular Gas: Computer Flash

[Kramer]

Is there any cost effective way to reflash the computer so a marauder can accept regular vs. premium gas?

[CRUZTAKER]

Cost effective?

Tuning / Flashing an eec by a proffesional is gonna cost atleast $150.

To answer your question however, yes. It can be changed via tune or flash.

I once had one of my 4 banks on my SCT chip programmed for 87 octane.
Occationally on long trips it can be difficult to find good gas.

[Bluerauder]

Cost effective?

Tuning / Flashing an eec by a professional is gonna cost at least $150.
It'll take about 15,000 miles of driving on 87 to recover your cost of the tune at the $150 price above. Not sure of the long term effects of running 87 in our engine ... but I don't think it can be good at all.

[MitchB]

Since my father only puts 89 octane in his Marauder, I tuned it run on this. I had to pull a lot of spark everywhere in the calibration. The way it is now, the car will just tag the knock sensors now and then, pulling no more than a couple of degrees. The car is not as snappy as it used to be.

Mitch

[duhtroll]

My stepdad also only uses 89, but in his case its because there is no 91 available without going some distance. Pull 2 degrees and it should be fine, but always listen.

[MarauderSM]

Im new to the forum, but the higher the octane the better the fuel efficiency, the more power that can be produced(safely), and the better the start up quality of the car.

[Stranger in the Black Sedan]

The 4.6 DOHC on 87? That's a new one by me.

[whd507]

all my OBD II fords get better mileage on 91 than 88/89 making my cost per mile lower with premium, than "cheap" gas. my 96 E-30 gets 40% better mileage on 91 than 88 (14 mpg vs 10)

my 95 TC gets much better on premium, as do my broncos.

the 20 cents a gallon difference,when gas is $3 a gallon is 6% higher initial cost, I bet you will always get more than 6% better mileage, especially in a marauder.

it just dosent make any sense to me.

[Bluerauder]

it just dosent make any sense to me.
I agree. There are too many down sides to running 87 including increasing the chances of permanently damaging the engine. Performance will be severely degraded and any perceived savings at the pump would likely be offset by lower MPGs. What's the point? :rolleyes: I can't get 91 in my area either .... so I use 93 exclusively. She likes it and keeps asking for more. :D

[duhtroll]

Except that 93 isn't available either in my stepdad's case, this might have been a viable option.


I agree. There are too many down sides to running 87 including increasing the chances of permanently damaging the engine. Performance will be severely degraded and any perceived savings at the pump would likely be offset by lower MPGs. What's the point? :rolleyes: I can't get 91 in my area either .... so I use 93 exclusively. She likes it and keeps asking for more. :D

[MERCMAN]

OK, 91 and 92 octane seems to be readily available in my area, I have to drive 15 miles to get 93. How much difference tune-wise and mileage wise is there with that 1 or 2 octane point??

[Bluerauder]

OK, 91 and 92 octane seems to be readily available in my area, I have to drive 15 miles to get 93. How much difference tune-wise and mileage wise is there with that 1 or 2 octane point??
I'd say that it can't be done. If you are driving 15 miles over and 15 miles back then you have just burned a minimum of 1.25 gallons of gas (probably more). That's about $3.86 spent in travel alone. At the typical 20 cents between the cost of 87 and 93/91 that I see here, you'd only save $3.40 on a 17 gallons fill up. You are two-bits in the hole even if you could get identical mileage out of the different octanes.

The owner's manual says the MM needs 91 Octane minimum. I see no inherent advantage to getting 92 or 93 especially if you are burning 30 miles worth of gas to get it. You would have to increase both your range and your MPG by 7% to even come close to making it worthwhile. And that doesn't factor in your time.

[MENINBLK]

The DOHC 4.6L Modular V8 in our Marauder can not be tuned to run safely on 87.
It has NOTHING to do with the timing or the gas.
It has EVERYTHING to do with the design of the combustion chamber.
There is too much Quench Area in our cumbustion chamber to run this engine on 87.

If you are unfamiliar with this term, I suggest you read up on it
and you will understand why we can't run 87 octane.

And when you are already spending over $3.00 for 87 Octane,
what is another 20 or 30 cents for 92/93 Octane ???

[Stranger in the Black Sedan]

There is too much Squelch Area in our cumbustion chamber to run this engine on 87.

Do you mean "Quench Area"?

[baltimoremm]

And when you are already spending over $3.00 for 87 Octane,
what is another 20 or 30 cents for 92/93 Octane ???

Agreed...Dont risk it. Substitute Ramen Noodles for one meal each week to offset the cost instead.

[Stranger in the Black Sedan]

Agreed...Dont risk it. Substitute Ramen Noodles for one meal each week to offset the cost instead.

LOL that is the best answer to someone trying to skimp by running 87 octane in a 300 horsepower 4200 pound car.

[fastblackmerc]

Im new to the forum, but the higher the octane the better the fuel efficiency, the more power that can be produced(safely), and the better the start up quality of the car.

Not true.

http://theserviceadvisor.com/octane.htm

http://stason.org/TULARC/vehicles/chrysler-general/12-Should-I-use-high-octane-gas.html

http://www.squidoo.com/regular_or_premium/

http://www.canadiandriver.com/articles/jk/040728.htm

http://www.trustmymechanic.com/htmlmessage21.html

http://chemistry.about.com/library/weekly/aabyb100401.htm

Google should i use higher octane and you'll get 1,150,000 hits that say basically the same thing "use the octane that the manufacturer recommends".

[ckadiddle]

Agreed...Dont risk it. Substitute Ramen Noodles for one meal each week to offset the cost instead.
I figure the Marauder expenses are my booze, cigarette and hooker budget.
:lol:

[rvaldez1]

Do you mean "Quench Area"?

I thought so too.

[fastblackmerc]

I figure the Marauder expenses are my booze, cigarette and hooker budget.
:lol:

Same here. I tell my wife that instead of spending money on my Marauder I can be spending it on women, drugs & liquor......

[MENINBLK]

Do you mean "Quench Area"?

Thanks for the correction...

[Stranger in the Black Sedan]

I know "Squelch" is a knob on my CB radio, that controls the cutoff level for background noise vs. signal.

[Kramer]

Thanks for all the help. I agree its not cost effective and sounds like it could be detrimental overall..

BTW...BLUERAUDER....how does 15 miles up and 15 miles back = 1.25 gals.

Since I do mostly city, I never see mileage above 15/gal...so thats more like 2 gals.

[Bluerauder]

Thanks for all the help. I agree its not cost effective and sounds like it could be detrimental overall..

BTW...BLUERAUDER....how does 15 miles up and 15 miles back = 1.25 gals.

Since I do mostly city, I never see mileage above 15/gal...so thats more like 2 gals.

I did say a minimum of 1.25 gallons. I gave you the conservative estimate and assumed you could get 24 MPG and use the highway to get to the station 15 miles away. Anything less is worse.

[sailsmen]

Lock out the throttle to limit use to the first 1/4.

Disconnect your COPS on 4 cyclinders.

It will drive like a Yugo.

[Stranger in the Black Sedan]

Disconnect your COPS on 4 cyclinders.

I don't think this will work -- won't the computer go nuts? Also, on variable displacement cars, they stop sending fuel and spark to the cylinders -- you'd be totally wasting the fuel to the dead cylinders without burning it. I think you'd get worse, not better, gas mileage this way, since you would not be getting the hp from the wasted fuel.