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
26,285

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
4,205

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
3,455

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

1 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

Galant
Looking for a Used Galant in your area?
CarGurus has 2,940 nationwide Galant listings starting at $1,600.
ZIP:

Search Mitsubishi Galant Questions

Mitsubishi Galant Experts

#1 dandyoun
dandyoun
Reputation 380
#2 Tom Demyan
Tom Demyan
Reputation 360
#3 Daniel Foster
Daniel Foster
Reputation 290
View All

Related Models For Sale

Used Mitsubishi Lancer"
105 Great Deals out of 4,428 listings starting at $1,995
Used Nissan Altima"
1,544 Great Deals out of 80,582 listings starting at $995
Used Honda Accord"
1,251 Great Deals out of 66,123 listings starting at $1,000
Used Toyota Camry"
1,586 Great Deals out of 70,498 listings starting at $1,395
Used Nissan Maxima"
607 Great Deals out of 19,661 listings starting at $1,495
Used Honda Civic"
843 Great Deals out of 57,416 listings starting at $995
Used Toyota Corolla"
1,207 Great Deals out of 54,848 listings starting at $995
Used Mitsubishi Eclipse"
65 Great Deals out of 1,985 listings starting at $1,700
Used Nissan Sentra"
654 Great Deals out of 35,036 listings starting at $1,500
Used Hyundai Sonata"
1,043 Great Deals out of 58,553 listings starting at $1,095
Used Kia Optima"
558 Great Deals out of 39,950 listings starting at $1,900
Used Acura TL"
277 Great Deals out of 6,664 listings starting at $2,250
Used Volkswagen Jetta"
1,078 Great Deals out of 37,069 listings starting at $1,995

Used Cars For Sale

2012 Mitsubishi Galant For Sale
62 Great Deals out of 1,057 listings starting at $7,946
2011 Mitsubishi Galant For Sale
21 Great Deals out of 352 listings starting at $7,695
2010 Mitsubishi Galant For Sale
8 Great Deals out of 180 listings starting at $4,995
2009 Mitsubishi Galant For Sale
9 Great Deals out of 272 listings starting at $3,999
2008 Mitsubishi Galant For Sale
4 Great Deals out of 83 listings starting at $3,500