We cannot help you if we don't know what car you have, what engine you have, what weight oil you used, what type and weight oil was in the vehicle previously, and if your driving habbits changed.

 

The car is a 2007 Camry. The I4 model. I used whatever Toyota recommends for the camry's. 5w20. I don't have the need for speed so i rarely step on the gas to accelerate.

 

The car is a 2007 Camry. The I4 model. I used whatever Toyota recommends for the camry's. 5w20. I don't have the need for speed so i rarely step on the gas to accelerate.

Here are some factors that could have made the difference:
1. Your new Mobil 1 was not kept at the same 5W20, maybe only 10W30 was available
2. Tire pressure dropped .
3. Outside temperatures fluxuated. Hot and humid weather decreases mpg
4. Air filter clogged
5. Change in driving patterns? Stop and go? Anyway-if you correct and adjust for the above it might all go back to before. Good luck!

 

Here are some factors that could have made the difference:
1. Your new Mobil 1 was not kept at the same 5W20, maybe only 10W30 was available
2. Tire pressure dropped .
3. Outside temperatures fluxuated. Hot and humid weather decreases mpg
4. Air filter clogged
5. Change in driving patterns? Stop and go? Anyway-if you correct and adjust for the above it might all go back to before. Good luck!

On the #1. What did you mean by that?

 

It means that if the delaer used a thicker viscosity oil it would affect mileage a bit. 10w30 is more common than 5w20 and they may have used a thicker oil. Call and ask them what viscosity they use.

 

Did you change the oil yourself?

 

Did you change the oil yourself?

my dad did

 

It is possible that the oil previously in the engine was 0W-20 (if that was the oil from the factor) so that would save a bit of fuel when the engine is cold.

If you have been doing more short trips and or stop and go driving than than before, that could account for the increased fuel consumption. If you have found yourself in more traffic than usual, that could account for the increased fuel consumption.

If the temperature has dropped, the fuel consumption will increase on startup because the engine will run rich when it's cold. Rich mixture is more stable than stoichiometric or lean mixture.

Since you only got 23 MPG, I assume you are doing mostly city driving or lots of stop and go. I drove 180 miles in my 2007 I4 Camry and used just over 1/3 tank.

 

It is possible that the oil previously in the engine was 0W-20 (if that was the oil from the factor) so that would save a bit of fuel when the engine is cold.

If you have been doing more short trips and or stop and go driving than than before, that could account for the increased fuel consumption. If you have found yourself in more traffic than usual, that could account for the increased fuel consumption.

If the temperature has dropped, the fuel consumption will increase on startup because the engine will run rich when it's cold. Rich mixture is more stable than stoichiometric or lean mixture.

Since you only got 23 MPG, I assume you are doing mostly city driving or lots of stop and go. I drove 180 miles in my 2007 I4 Camry and used just over 1/3 tank.

Yeah i mostly drive in the city. I guess I have been stopping a lot.

 

If this were my car, i'd suspect the Mobil 1 for the drop in mileage as the very last thing that would have caused it. Mobil 1 is the best oil you can get and is more "slippery" than any old dino oil - i'd think it had some other cause as the others are saying.

I find that my mileage gets "better" somehow, the more miles i wait to fill the tank and check mpg! Without a scientific test there's a whole lot of variables to affect mileage so my guess is like i said, i believe it has nothing to do with using Mobil 1 oil.