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
25,565

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
295

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
4,035

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
3,265

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

Your Answer

Related Questions

Galant
Looking for a Used Galant in your area?
CarGurus has 2,741 nationwide Galant listings starting at $1,500.
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 260
View All

Related Models For Sale

Used Honda Accord"
1,404 Great Deals out of 73,643 listings starting at $1,000
Used Mitsubishi Lancer"
112 Great Deals out of 4,137 listings starting at $1,995
Used Honda Civic"
858 Great Deals out of 48,022 listings starting at $1,295
Used Nissan Altima"
1,763 Great Deals out of 73,482 listings starting at $1,587
Used Mitsubishi Eclipse"
79 Great Deals out of 2,120 listings starting at $1,495
Used Toyota Camry"
2,067 Great Deals out of 73,889 listings starting at $999
Used Nissan Maxima"
686 Great Deals out of 20,364 listings starting at $946
Used Chevrolet Malibu"
1,644 Great Deals out of 63,709 listings starting at $750
Used Toyota Corolla"
1,369 Great Deals out of 45,476 listings starting at $990
Used Nissan Sentra"
690 Great Deals out of 28,416 listings starting at $1,495
Used Hyundai Sonata"
1,163 Great Deals out of 50,081 listings starting at $990
Used Mitsubishi Lancer Evolution"
23 Great Deals out of 903 listings starting at $13,995
Used Mitsubishi Diamante"
197 listings starting at $2,500
Used Kia Optima"
555 Great Deals out of 36,837 listings starting at $1,900

Used Cars For Sale

2012 Mitsubishi Galant For Sale
51 Great Deals out of 763 listings starting at $9,595
2011 Mitsubishi Galant For Sale
16 Great Deals out of 326 listings starting at $6,900
2010 Mitsubishi Galant For Sale
13 Great Deals out of 181 listings starting at $6,999
2009 Mitsubishi Galant For Sale
12 Great Deals out of 320 listings starting at $3,999
2008 Mitsubishi Galant For Sale
3 Great Deals out of 70 listings starting at $3,994