mileage down not up???

[cparkerc]

2006 Sport V6 -Just changed the gear oil in the front and rear diffs and transfer case. The rear was pretty dirty. Used amsoil severe gear 75w-90 . I expected the mileage to go up, but the computer is reading lower than normal.

Anyone else experience this?

Thanks,

Carrington
Fort Collins, CO

 

[cparkerc]

Let me ask a different way...

I guess I didn't ask my question very well, let me try it again:brick::brick:

OK, Could I have done something incorrectly when I changed out my fluids? I was getting 18 - 19 mpg and now it has dropped by about 2 mpg without any changes to how I drive.

Do I need to reset everything by unplugging the battery?

Thanks!

 

[Adumb]

I guess I didn't ask my question very well, let me try it again:brick::brick:

OK, Could I have done something incorrectly when I changed out my fluids? I was getting 18 - 19 mpg and now it has dropped by about 2 mpg without any changes to how I drive.

Do I need to reset everything by unplugging the battery?

Thanks!

I think I remember my mileage dropping slightly when I changed my gear oils. I dont think by 2 mpg though.

Could be the new oil being more viscous is hurting the mpg's. I bet the gears are loving the new oil!

 

[BlackWorksInc]

The Toyota Optismism meter isn't a very good indicator of fuel mileage in my honest opnion... I still haven't figured out EXACTLY how it gets its numbers... (there's a thread I made buried somewhere on here regarding it)

It could be a lot of things to be honest with you... one thing I have noticed that Toyota's don't do that some other brands like BMW, Ford, ect... do is that they won't go back up. i.e. you're coasting down the Grapvine in 5h gear, not touching the gas and somehow you still have 16mpg on the Wish-O-Meter, when in reality you probably freed up a bit more gas mileage, assuming the rest of the trip isn't stomp happy.

 

[V8Man]

At work on a gear set much like a truck. It was actually on let's say a tractor. We experienced high gear wear and overheating that was caused by too much oil in the box. Make sure your rear end isn't too full. Nothing worse than a full rear end!
Seriously gear oil needs the space for cooling.

 

[Gecko123]

I guess I didn't ask my question very well, let me try it again:brick::brick:

OK, Could I have done something incorrectly when I changed out my fluids? I was getting 18 - 19 mpg and now it has dropped by about 2 mpg without any changes to how I drive.

Do I need to reset everything by unplugging the battery?

Thanks!

Couple of things the built-in MPG is not that accurate. Secondly, changing the gear oil will have little impact on MPG.

 

[JB.]

Yes, this is an mpg measurement problem, not a gear oil problem.