Declining MPG in 2004

[bwilson4web]

Originally Posted by smithBYU85

... Do you think changing those fluids (coolant, transaxle, etc...) would make a big difference?
...

Before changing my transaxle oil, I did a series of 'hill rolling tests' in cold weather and found the first change made a significant improvement. If you plan to change the transaxle oil, see if you can find a very shallow hill near your home that you can do a "roll down" test over a week. You want the start to be such that your car comes to a stop by itself, using "N" and the engine off _IF_ _SAFE_.

Get the transaxle oil changed and repeat the hill roll down test and share the results.

I have not been able to do a 'warmed', hill rolling test. Even the old oil, when the car was warmed, would reach the end with significant velocity. In my case, the temperatures were around freezing.

Also, what are your front and rear wheel alignment numbers? Rough roads or stress can throw the toe and camber off enough to increase tire drag. Also, what tire size, make and model, are you running now?

Rolling resistance is bad news because it robs performance all of the time. That is why my first efforts have and remain focused on reducing rolling resistance.

Bob Wilson

[mikepaul]

Originally Posted by smithBYU85

I don't mean accelerate so slowly as to make other drivers mad at me, but to keep from really revving the engine. I haven't decided if a slow acceleration or a brisk acceleration to the speed limit is the best, I'm still evaluating that.

That 'revving' thing does eat into your MPGs, but normally a brisk takeoff doesn't do that if your drive battery is happy.

Ever since it got HOT here, I've had battery issues where it goes pink on me almost daily. It's an odd cycle: when it's pink the engine runs more (POOR acceleration since the electric motor won't help) followed by not-quick recharging until everything is normal again. Then later, when going up more than a few hills, I'll notice that the battery is low again like it 'forgot' to maintain charging. I'm wondering if the vent in the backseat needs cleaning or something, to get more of the A/C down there to help the battery...

[smithBYU85]

Originally Posted by bwilson4web

Also, what are your front and rear wheel alignment numbers? Rough roads or stress can throw the toe and camber off enough to increase tire drag. Also, what tire size, make and model, are you running now?

Rolling resistance is bad news because it robs performance all of the time. That is why my first efforts have and remain focused on reducing rolling resistance.

Bob Wilson

I waited to post so I could try to find those numbers, the dealer gave them to me when I changed my oil a few weeks ago but I can't find the paper that they gave me. If I find them I'll get back with you. I'm about to move out of my apartment so I have stuff in lots of places while I pack.

[richard schumacher]

Originally Posted by smithBYU85

- I drive with the A/C off as much as possible despite the 90+ temps here

BZZT! *Do* use the A/C, because it also cools the battery system. If you feel too warm then so does the battery. When the battery gets too hot it will throttle itself, and that reduces MPGs.