Changing The Oil and Gas Mileage?

I have a 1988 Ford Ranger V6 2.9L. I have had this truck since about March of 2007. When I first bought this truck I could run about a week for $25 and at a gas station with gas the same price it was when I bought the tank it cost me $40 and thats if I drive the same number miles each week. I changed the oil today and the old oil was solid black. Could the old oil that was in it be what was causing me to get such bad gas mileage?

10 Answers

  • 1 decade ago
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    Dear Ranger-

    Lets do a little Automotive 101 together shall we?

    Oil perfroms several functions within the engine. It lubricates, cools, flushes away debris, carries this debris to your oil filter and protects the moving parts within your engine.

    You may have encountered the statement that the oil does not wear out. That statement is only partly true. The base stock, (the actual oil), does not wear out. However, the detergent packages that are engineered with the oil to improve its lubricating and cleaning properties does. This is the reason for frequent oil changes.

    The rule of thumb is every 3000 miles or 90 days whichever occurs first. This ensures that the additive packages in the oil are not overloaded and unable to perform their tasks of cleaning and lubricating the moving parts.

    Failure to change engine oil is a major contributor to engine sludge buildup, excessive wear and heavy oil consuption directly related to this engine wear.

    As for your vehicle, the person who told you to use Straight Weight Oils rather than the Multi-Viscosity Oils is incorrect. Straight weight oils produce more engine wear on cold start-up than the Multi-Grade Oils. This is very important because we are now coming out of the summer months and entering into the colder months of the year.

    On your Ford Ranger, (depending on milage), I would reccommend that you use 20w-50 weight oil in that engine from now on until you sell or retire the vehicle.

    Here is a guide that you can use. We use this guide in the field to determine what oil to use with what vehicle.

    New Vehicle, (0 to 30,000 Miles):

    5w-30, 10w-30

    Intermediate Vehicle, (30,001 to 70,000 Miles):

    10w-30, 10w-40, 15w-40

    High Milage Vehicle, (70,001 to 100,000+ Miles):

    15w-40, 15w-50, 20w-50

    There is a good chance that the oil was contributing to the poor fuel milage, but not to the point at which you described. This is normally a sign that the engine may be due for a good tune up, and general service.

    This may include all of the following:

    Spark Plugs

    Plug Wires

    Distributor Cap

    Distributor Rotor

    Air Filter

    Fuel Filter

    PCV Valve

    Engine Oil and Oil Filter

    Cooing System Service

    Transmission Fluid Service

    Fuel Injector Service

    Rear Differential Service

    This would be considered a major tune up on your truck, and if it has not been done since you owned it, I would highly advise that it be done along with a complete diagnostic to ensure all of the other systems are functioning properly.

    Poor fuel economy can also be attributed to:

    Low Tire Pressure

    Incorrect wheel alignment

    Malfunctioning Emissions Equipment

    Malfunctioning Fuel Management Systems

    Excessive Engine Wear

    Low Compression

    Transmission Malfunctions

    This is why I made the reccommendation to have the vehicle diagnosed in a reputable shop or your local Ford Dealership's Service Department.

    Yes contrary to what you may have been told, Ford will still service this truck for you. The Dealerships are not just for the newest cars and trucks on the road. They will service this truck for you, and probably be able to provide you with a more complete diagnostic as to what all of the issues are facing this vehicle, and whether its worth you time to keep the truck, sell it or trade up for a new one.

    Of course if you are going to keep it then by all means have them service the truck for you. Remember the Dealerships are going to be more expensive to have your vehicle serviced, but the service they provide is normally better, the environment in which you are greeted is normally clean and friendly. Dealerships also maintian the most current and up-to-date service information for your vehicle. Ford is just like GM in this area. All of the Dealership Service Departments are constantly updated with factory service information. So if there are any warranty recall, (campaign) items that need to be addressed, they can and will handle it right there.

    These business also keep record of your service intervals, and the services and/or repairs that have been made to your vehicle. This is very important if a part failure shoudl occur, they can cover it for you with very little hassle.

    Lastly. Once you have started with a particular brand of oil, you need to stick with that brand of oil. Switching brands to suit what is on sale is an excellent recipie for engine sludge build-up.

    I hope this helped you out. Good Luck!

    Source(s): General Motors Service Parts Pro
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  • 1 decade ago

    Oil is the blood in ur car n should b changed every 3000 miles, specially since it's from 1988. R u carrying lots of dead weight on ur truck? R u accelerating more than usual after a red light?

    Any truck/car/SUV w/ a proper tune-up will run better n increase ur gas mileage.

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  • 1 decade ago

    old oil will affect the mileage very little, the thing that it probably needs the most is a good tune up,those was pretty good little engines,but you had to keep them tuned really well,the oil will not make that much difference in the mileage,id say its in need of a really good tune up,that would help it more than anything,do that and your mileage should come back up on it,also be sure and check and replace the air filter and gas filter if needed,good luck with it.

    Source(s): been a certified mechanic for 37 yrs.
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  • Yes regular oil changes help the mileage. For a truck that old, try using SAE 30 or 40. Do not get 10W-40 because the viscosity is not enough to hold off the heat from the old engine. In fact, if you can get Diesel engine oil, it will last longer. It will help also if your engine is burning oil, which it probably is.

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  • 1 decade ago

    Oil always makes a difference. On high mileage engines it's all you have to keep the power and mileage running they way it should. If your oil was solid black you may want to look at using a little heavier oil. or changing the oil every 2000 miles instead of every 3000.

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  • Anonymous
    1 decade ago

    What everyone else said is true, but consider one other thing. The next time you buy gasoline look at the pump. Is there a sticker on the pump that says 10% ethanol blend or something to that effect? Oil companies started blending gasoline with ethanol and most gas is that way now. I'm not referring to E85 flex fuel but normal gasoline. It certainly won't hurt your vehicle but it does reduce your fuel economy as much as 3 or 4 MPG.

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  • 1 decade ago

    Yes, bad oil will hinder gas milage. I found that when I changed with synthetic oil, I did gain about 10% in my MPG.

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  • yes you should change the oil at least every 3000 miles and the air filter every 6000 miles also the fuel filter should be changed every 6000 miles when using regular gas.

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  • Anonymous
    1 decade ago

    That could be part of it. You might want to consider a tune-up and filter change, also.

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    Lv 4
    1 decade ago



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