Gas Mileage & Odometer Accuracy: 4.0 V-6 DC 4WD

Did a nearly 900 mile (round trip) highway trip to Tucson, Arizona from the San Diego area.

Ran east bound using 91 octane Premium from Shell and Chevron and ran west bound using 87 octane from the same two companies.

My 2010 4 door, 4WD V-6 Automatic Tacoma (67,000 miles) had no cargo or passengers, just me and my over-night bag and some drinks in a cooler.

I have 265/75-16 tires (Destiny Dakota ATs). The speedometer which ran fast with the stock 265/70-16 tires (reading 70 when I was going 67-68 per the GPS) now reads correctly.

I checked the odometer over a 40 mile highway stretch east of Yuma. At 40 miles, my odometer read 39.0.

This shows that Toyota makes the speedometer read a little faster than you are really going (to keep you from getting tickets?) but the odometer is perhaps accurate at the same time.

The approx. one inch taller tires will give you less mileage on the odo than you actually travel. This gives you 'poorer' mileage, besides any mileage loss from bigger, heavier, aggressive tires you may use.

I drove the signed speed limit or within 2 mph. It was 65 & 70 in California and 65 & 75 in Arizona (with a short 55 section). I topped off before the highway drives, so no in town driving was included.

Going to Tucson on 91 octane I got 18.3 and 18.4 MPG with my two fill ups. Adjusted for the odometer error it is closer to 18.8 and 18.9 MPG.

Going back to San Diego area was on 87 octane I got 19.6 and 17.7 MPG with the two fill ups. Adjusted for odo error it is 20.1 and 18.1 MPG.

19.10 MPG avg. on regular 87 octane.
18.85 MPG avg. on premium 91 octane.

So close as they are nearly identical, but the better figure is regular grade gas, even if they were the same... no reason to buy premium.

The gas in Arizona is about 50 cents a gallon cheaper than here and the pumps there (as they do here) are labeled as containing up to 10% ethanol.

This is the best mileage I have recorded (Tucson to Yuma) beating the previous 19.2 mpg I recorded in Mexico using ethanol-free Pemex gasoline (87 octane). I was heavily loaded for camping and driving fast. Under similar conditions as I just drove, I believe with Pemex, I would be well over 20 mpg.

On the San Diego B.S. forum, I also posted my driving times from here to Tucson and back, if anyone is interested... 7-8 hours with rest stops and lunch break.

 

No comments, questions or arguments?

 

WOW , Tacoma's get crapy gas mileage ,

 

Going Tucson is uphill.

Back is down.

 

There is a 4,000 foot + mountain in San Diego County Hwy 8 goes over... so anything east of that is pretty darn flat in comparison.