I have a 2007 camry hybrid and generally have gotten 38-39 mpg. I recently have my oiled changed and decided to go with the synthetic oil because I'd heard it would last a little longer and slightly increase mpg. After the oil service I filled up my tank and was surprised when I averaged about 31 mpg. The tire pressure wasn't off and after 2 more tanks of gas my mpg remains about 31 mpg. I'm puzzled. Anyone have any ideas what might have caused this sudden decrease. Thanks.

 

Did you change oil grades? e.g. 5w-20 to 5w-30? Not sure what Hybrids use.

 

it could also be the winter gas. my 5sfe gets crap normally around 20 if im lucky but since they are getting the winter gas im getting about 3 to 5 mpg less. idk if the drop it more extreme in the hybrids. just be lucky you are getting that much.

 

Colder Winter air temps would slightly increase your MPG so a dip is odd. Hybrids work a bit differently, but in a standard engine, it's not uncommon for the engine to need some "adjustment" to a synthetic oil. That could be the explanation, but I don't know why it would be so dramatic. Should have been maybe a 1-2 mpg, not 7-8.

For future reference, the only vehicles that really benefit from synthetic oil are high-performance. Corvette, high-end Lexus, Viper, etc. The average vehicle (like Toyota) doesn't need it. Its a lot of added expense for little or no benefit. A higher octane fuel might give you more benefit, but some say even that is not worth the extra $0.20/gallon.

 

Hey, thanks for the comments. I can't remember what oil weight I got with the synthetic oil but since winter is coming on I would have chosen a thinner oil if I changed the grade. New tank of gas a couple of days ago and now struggling to get 28 mpg.Is there any harm in going back to regular oil at my next change? Could it actually be the gauge itself is miscalibrated? Still befuddled.

 

Check your manual, Toyoyta would have recommended a year round oil I'm thinking, even synthetic. Synthetic will flow better in cold weather, withstand heat better and last longer between changes. In fact you'd be smart to use the full extent of the oil's life between changes to reduce oil change intervals (OCI) and get back some or all of the extra cost of the oil. I'm able to double my OCIs with synthetic and have great oil analysis results (low wear). BecauseHybrids use the electricmotor to offset fuel use the cut-in/outparameters of the switch-over may be off. This being an 07I'd take it in to Toyounder warranty to see if some computer settings are off. Might also be somethinglike a dragging brake caliper or emergency brake.

 

Update on lousy camry mileage......OK, I took my camry hybrid to the dealership and sho' nuff by the time I get there I'm getting 33-34 mph (instead of in the twenties). Not as good as 38-39 I was getting but I'm thinking maybe some blockage got dislodged or some other thing got straightenedout and 34's not too bad. The dealership said everything looked fine but the winter gas is a b*tch on mileage. Tire pressure good, synthetic oil good, etc. I leave thinking OK it's the winter gas.....but now I'm back to 28 mpg and figuring I'll just have to monitor it until spring and see if it changes. Thanks for the tips

 

What kind of gasoline did you use. Gas with alcohol will lower MPG by 10% in most engines.

 

What kind of gasoline did you use. Gas with alcohol will lower MPG by 10% in most engines.

 

How fast are were you going at optimal mpg versus low mpg? that usualy is whats going on as far as changing mpg gauge. rpms, speed, passengers, etc all adds up big on gas milage.If you did not makeany changes thenit could be your ecu changing mixtures etc. the newer car's ecuscan change fuelto air ratios etcwhich could be dropping your mpg. quite honestly i hate new computer systems because they constantly adjust and make performance mods 100 times more hard to do and screw up dyno data due to their adjusments.