MPG study

Hi all,

Just want to run my MPS #s by you to get some (intelligent ) feedback.

I have attached my MPG spreadsheet for your study. While I dont list the ambient temps, they have been on the colder side here in Orlando, between 45 and 70 for the highs. I'd guess the avg temp while driving has been 60F.

Just bought the car. It came with new tires but they are an off-brand, likely the cheapest available to the dealer I bought the car from. I set the pressure to 42/40 psi. Battery voltage was 12.00V after sitting overnight. I have not used the A/C or headlights. I drive the speed limit, accelerating slowly. I coast down a lot. I think I drive the way I should in order to maximize MPG without using the PnG or some other inappropriate way of driving the streets of Orlando. All flat roads here. The display speed and distance traveled match 2 GPSs I have within 1% or less. Most of my trips logged here are my daily commute of 45 miles each way, with about 35% of that being at 65mph.

So, is my real MPG of 41.0 (from fill-ups) normal? Seems to be a bit lower than I expect after reading endlessly on this site. Maybe 45-48 should be right? The 1000 miles of highway at 72 mph gave a 40.5 MPG readout. Taking that out of the data, I guess I'd have about 43 MPG.

Also, a 9% disagreement with the display seems high, it gives 44.8. Is this normal? Didnt see this discussed explicitly yet. I'm sure its just an honest mistake on Toyota's part.

Also attached is a quick study I did of Display MPG vs. Speed with a 70F ambient over about 2 flat miles for each data point.

Enjoy!

 

Thanks for the thoughts Tom. I thought that the 50 gals so far would be enough to factor out much of the bladder volume variation--maybe not. Just remembered, the tires are "Doral" brand, whatever that is. Never heard of them. They will probably last a long time so that I cant get the nice GoodYear's (I should be using) anytime soon.

Yeah, the bladder stinks. The most I've been able to put into the tank was 8.6 gals--about 25 miles after the last pip started blinking.

 

But since the displayed speed checked out OK vs. the GPSs, I gave up on it.

 

Thanks for the comments.

Most of my trips logged here are my daily commute of 45 miles each way, with about 35% of that being at 65mph, the rest at 40 mph avg I guess.

 

Filled to MAX, not over. Not synthetic.

What other sensor could be cleaned besides the MAF?

Also, have not heard of the brakes dragging so far. I'll search. I do get a slight squeeking sometimes from the front.

Off the get some MAF sensor cleaner...

 

I cleaned the MAF sensor. It was not visibly dirty in any way. I'll see what that does.


Also checked the battery voltage again. Got 12.35 this time. Last time it was 12.0. Not sure why the difference. Same time since it had run--after sitting overnight.

I'll check the rear brakes next.

 

I adjusted the rear brakes. They were not really dragging much at all. I did however notice that the right rear bearings are going. They do not move as easily as they should and there is a slight notchy felling to them. With only 33k miles I did not expect this from Toyota. Even though I am past the 3/36 warranty, I'll still try the dealer to see if they will replace it. Bet they wont though.

 

Doral sdl65 or something like that. I did look them up and found they are cheap but have decent temp and traction numbers. I'll get the alignment checked but already know they will tell
me it is needed. That's what they do.

Thanks for the suggestions.

 

OK, so now I got a 9.75V reading after the car sat in ON with the radio on for about 45 mins. After I started the engine it goes to 13.75V, then to 12.4 after the ignition has been turned OFF for 5 mins.

Dying 12V battery?

 

Had another reading of ~10V after just sitting overnight.

Nipping this in the bud.

Just ordered the Optima battery and kit. I'll post MPG results after I get enough data.

 

New Optima yellow is in. Give me a week at least to report back on mpgs.