Fuel Mileage

[Crawler]

One thing you have to keep in mind also is the weather. Engines like the cooler weather and really don't care about really hot and cold months.

Sent when I should be working.

 

[Grad12]

Spark plug change (if you haven't already), inflate the tires to max setting and let them drop down over the next 6 months and then inflate again, run some cleaning agents in your gas just a couple of times (I recommend lucas oil upper cylinder lubricant, it works very very well), or seafoam (because degunking your egine makes a huge difference), make sure your air filter is clean and/or change it, change your oil and run synthetic every 5000 (km's for me -- canuck), change your tranny fluid and dif fluids, change out the brakes.

Your basic maintenance helps keep gas mileage where it is supposed to be. A good oild change does wonders I find.

Good luck.

 

[dtru1222]

Your saying a catch can will increase fuel milaege??

I agree with crainor. Most people don't do statistically significant studies with well controlled environment to prove that a mod increased MpG or power. Worse yet, if the measurement instrument is EVIC, the results cannot be trusted.
A higher flow filter is meaningless in a stock engine stock ECU; the engine will retard it's call for air to ensure a constant flow. You can remove the filter and see no difference. You must have a proper computer tune to call for more air.
A catch can COULD improve longevity, maybe, but it will not increase MPG.
Most mod claims are linked to salemen or those who purchased and trying to justify the expense. Yes these are generalizations, that apply to the average stock setup where someone is exploring bolt ons.

A bypass tuner is a great example. Many will claim they see EVIC MPG improvement but this is not real. The ECU computer is purposely fooled/hidden from extra gas delivered for the increased power, thus understating MPG.
Retrax claims my bed cover saves 10% in fuel. After 7800 miles, there is absolutely no difference in economy. None, as expected (I bought for function only).

There are no easy low dollar magic improvements to MPG improvement; if there were, the manufacture would have made them standard to improve competitiveness and get the Government off their backs.

I have tested the EVIC on all 4 of the vehicles I have owned and each one was within 1mpg of the hand calculated numbers. There are a few that have shown that their EVIC is off but most can be chalked up to fudging the numbers.

yes, to get the most out of the increased air you would need to tune. But that does not mean that you gain absolutely nothing from freeing up the restrictions. If your engine can breathe easier you will benefit from it. Like I stated each one of the mods I added increased the MPG (except for long tubes).

I would like to see these studies that showed no gain in mileage. Do you have any links? Always interesting to read.

I am not a salesman, and I also do not want to say that adding a catch can will absolutely increase MPG. The possibility is there, but will vary from car to car. If you are suffering from reduced timing from Knock Retard (5+ ST) then I will go out on a limb and say that yes, you will see a slight improvement since it will help curb the timing retard which will in turn increase performance and MPG.

The tuners do not "fool" the ECU into thinking that its getting increased MPG (well I will say that for the DS tuner). I have verified this by hand calculating while also testing the EVIC. On my GF's v6 Charger I installed the 91 canned tune, filled up with 93 octane and took a 400 mile round trip. The EVIC showed 38 MPG and the hand calculations were 37.6 IIRC.

 

[Oilbelcher]

Agree it's not the case that some bypass tuners intentionally fool the on board computer to increase MPG. It tricks the system to deliver more gas and with this process, the computer doesn't see the extra gas delivered. Remember that an EVIC type took is estimating gas volume, not measuring it (like a gas station), using parameters like number of injections, rpm, etc.

If you have that severe of a knock problem, I wonder about bad quality gas, high ethanol or other problems. But yes I can see how knock prevention can prevent a loss in HP, rather than a gain above stock figures.

I have extensive history of hand calc fugues on multiple brands. All the on board figure were high. Also remember that being close to actual hand calc can be luck. The computer doesn't track MPG over one full tank of miles. Only tracks the most recent ~209 miles. You can prove this to yourself by tracking EVIC frequently and see how ridiculously fast the MPG fugues can move up or down based on very recent changes in driving style.

My Mercedes and Infinitis had 10,000 miles before a K&N CAI install. The next 10,000 miles showed 0.0 difference in MPG, all hand calculated. I never miss a fill up when tracking. Butt dyno showed nothing, and to my initial frustration but knowledge gain, a dyno showed no more than 1-2 HP gain at super high unusable rpm. No use in normal everyday.

 

[dtru1222]

Agree it's not the case that some bypass tuners intentionally fool the on board computer to increase MPG. It tricks the system to deliver more gas and with this process, the computer doesn't see the extra gas delivered. Remember that an EVIC type took is estimating gas volume, not measuring it (like a gas station), using parameters like number of injections, rpm, etc.

If you have that severe of a knock problem, I wonder about bad quality gas, high ethanol or other problems. But yes I can see how knock prevention can prevent a loss in HP, rather than a gain above stock figures.

I have extensive history of hand calc fugues on multiple brands. All the on board figure were high. Also remember that being close to actual hand calc can be luck. The computer doesn't track MPG over one full tank of miles. Only tracks the most recent ~209 miles. You can prove this to yourself by tracking EVIC frequently and see how ridiculously fast the MPG fugues can move up or down based on very recent changes in driving style.

My Mercedes and Infinitis had 10,000 miles before a K&N CAI install. The next 10,000 miles showed 0.0 difference in MPG, all hand calculated. I never miss a fill up when tracking. Butt dyno showed nothing, and to my initial frustration but knowledge gain, a dyno showed no more than 1-2 HP gain at super high unusable rpm. No use in normal everyday.

I dont know what vehicle you have but in all of the 09+ Dodge/Ram you can reset your MPG in the EVIC. I reset it when I fill up and calculate when I run it empty and refuel again. No luck involved and the results are consistently within 1 mpg of each other.

If I do not reset it and run several tanks it does not fluctuate that much but stays near one number. The more miles I put on it, the less it fluctuates.

This is where I get my proof that the tuner does not "trick" anything to read higher MPG. Whether it can read how much fuel its pumping or not, the average MPG went up on both the EVIC and hand calculations and both were withing 1 MPG of each other every time I tested it.

Gas quality in the DFW area is horrible. I tried several different stations and the best I can find is Chevron.