Gas mileage seemed to recently decrease from 280 miles (full tank)to about 210 miles. What can be the problem?

djc77
0

Asked by djc77 Feb 13, 2008 at 06:03 PM about the 2001 Mitsubishi Galant ES V6

Question type: Maintenance & Repair

I do oil changes every 3000, change air filter every 12000, and had a full tune up at 68000 miles. I now have 75000 miles on it.

7 Answers

papa
Not Active

it is not unusual to lose some millage with age of cars ,also todays gas is junk,if running reg,run mid grade with a bottle of good fuel injector cleaner-lucus is great.

littlehorn
25,825

How has the weather been? I notice a decrease in gas mileage here in PA in the winter on the colder days. Basically, gas is not always the same density -- when it is hot out, gas is less dense, when it is cold, gas is denser. So when it is cold the same volume of gas that is fed to the fuel injectors is not the same volume as in the summer months.

Rishi Patel
135

Bad gas, dirty injectors, dirty air filter, spark plugs, timing, air to fuel ratio etc.

1 out of 1 people think this is helpful.
Matt Rodriguez
305

Timing? The ECU in these cars controls the timing. No matter what you do to try and adjust it, the ECU will just correct it to the proper adjustment. and A/F Ratio? Are you kidding me? This is something you cannot touch on these cars without any type of standalone tuner. All of this is preprogrammed into the ECU, and I highly doubt he is adjusting these settings from a tuner. And to the person above talking about going from regular unleaded to mid-grade unleaded, don't be so clueless. The 6G72 in his V6 Galant requires Premium Unleaded. True he might not be using the required Premium, but for the extra $1-$2 it costs per tank, it would be completely stupid not to use the correct fuel. Sorry. /rant, but I hate when people give B.S. info that in no way will help the OP figure out what he is posting for.

Adam Morgan
4,085

When did this start exactly? If it was shortly after the 'full tune up', it could be plugs were not gapped properly... It could be one of the many sensors that corrects the A/F ratio is dirty and throwing the mixture off... It could be a dirty fuel filter... It could be dirty injectors... It could be dirty valves... It could be that the gas station you get gas at has newer pumps that now are out-stopping sooner and you have slightly less gas in the tank... It could be the valve cover gasket is leaking into the plug wells and acting as a dielectric reducing spark propagation... It could be several other things... There is a decent list of what the problem could be... So where to start is your next question, right? 1) Pay attention to MPG in the future not miles per tank because how close to full you get depends on the gas station. 2) Injector/Intake cleaner... Not just the little bottle that goes in your tank but the two stage that includes running a cleanser through your vacuum lines to the intake manifold... Seafoam is the DIY'rs brand here. 3) Fuel Filter (If it's serviceable on your car... Some aren't... some are really hard to service(Inside the gas tank, but still supposed to be replaced)) 4) If your still having problems, pull your plug wires off the plugs and make sure there is no oil around the bottom... (Would mean a leaking valve cover gasket... a simple problem, but an annoying and often overlooked one)... While you're there pull at least one plug and make sure they were gapped correctly and that they aren't fouled up... If you're STILL having problems or have any questions post back...

1 out of 1 people think this is helpful.
crawfishaholic
35

The use an fuel injector cleaner on a regular basis is one answer to your problem. Another is if the car has been only in city driving is would be best to get a long highway at a steady speed at 70 -75 mph for about 1 hour one way. This will allow to blow out carbon buildup on your engine. Making it more efficient.

Daniel Foster
3,315

a little late to the party aren't ya there crawfish ? lol

Your Answer

Add photo

Related Questions

Galant
Looking for a Used Galant in your area?
CarGurus has 2,543 nationwide Galant listings starting at $1,195.
ZIP:

Search Mitsubishi Galant Questions

Mitsubishi Galant Experts

#1 dandyoun
dandyoun
Reputation 380
#2 Tom Demyan
Tom Demyan
Reputation 340
#3 Daniel Foster
Daniel Foster
Reputation 270
View All

Related Models For Sale

Used Honda Accord"
1,444 Great Deals out of 66,644 listings starting at $995
Used Mitsubishi Lancer"
111 Great Deals out of 4,001 listings starting at $1,993
Used Nissan Altima"
1,995 Great Deals out of 73,042 listings starting at $1,000
Used Honda Civic"
922 Great Deals out of 49,340 listings starting at $1,600
Used Toyota Camry"
2,020 Great Deals out of 75,811 listings starting at $1,007
Used Mitsubishi Eclipse"
86 Great Deals out of 1,899 listings starting at $1,395
Used Chevrolet Impala"
1,756 Great Deals out of 55,004 listings starting at $999
Used Toyota Corolla"
1,422 Great Deals out of 47,416 listings starting at $1,488
Used Volkswagen Jetta"
1,045 Great Deals out of 40,519 listings starting at $1,595
Used Nissan Maxima"
691 Great Deals out of 19,329 listings starting at $946
Used Chevrolet Malibu"
1,718 Great Deals out of 64,609 listings starting at $1,200
Used Mitsubishi Lancer Evolution"
23 Great Deals out of 857 listings starting at $9,988
Used Mitsubishi Diamante"
171 listings starting at $2,500
Used Kia Optima"
575 Great Deals out of 37,391 listings starting at $1,900
Used Acura TL"
312 Great Deals out of 6,380 listings starting at $1,000

Used Cars For Sale

2012 Mitsubishi Galant For Sale
55 Great Deals out of 765 listings starting at $9,388
2011 Mitsubishi Galant For Sale
17 Great Deals out of 315 listings starting at $6,900
2010 Mitsubishi Galant For Sale
9 Great Deals out of 184 listings starting at $5,142
2009 Mitsubishi Galant For Sale
15 Great Deals out of 290 listings starting at $3,999
2008 Mitsubishi Galant For Sale
68 listings starting at $3,994