bulldog-yota

I have a '03 4Runner Ltd V8 4WD, and found that the gas mileage indicator consistenly shows 2-3 MPG more than it actually gets! I checked the odo with my GPS and it only slightly underreads. I normally get 17-18 MPG in reality, but it shows 20-21 MPG.

Anybody else getting this? ANy fixes yet?? Or just take back to dealer at service.

FirstToy

I think they all do that.

Lance wrote something about how the computer calculates mpg's...I forget the link tho.

Good Times

The heck w/ the link... Cuz I don't even remember where I wrote that Sometimes searching takes way too long for myself looking for my own stuff... lol

Problem w/ the calculation is simple. The engineers made the calculation to be more flexible thus only taking calculations at specific intervals. The problem is that the error becomes amplified when not calculated at every change. Change which is not controllable as there is really no accurate way to calculate this.

Ideal conditions state that you calculate the miles driven divided by gallons consumed. But during realtime, it just can't be done. Therefore the computer then reads your current travelling speed (MPH) and calculates it according to your gas tank level. Obviously the tools that use this measurement will not be exact and will have errors. Errors also associate when you don't calculate every second or every mili-second so you'll get greater errors.

The problem w/ calculating constantly will result in figures that jump from 0-infinitely depending if you are flooring the vehicle or coasting. I've seen my reading read 99.9 and as low as 1.2 or something like that. Obviously that is incorrect but the computer is unable to adjust that quickly.

Basically, it's just guestimating your mpg so don't bother figuring it out. They'll never have a fix on this so it's a waste of time. Just use the miles left as that's okay (not exact either) but if you want something better, just use the temp reading... but then again that's not accurate too... ahhh fubar... damn computer readings...
Just be happy to get some great readings like that!!! I get just about 300 miles on the range and about 10-12 reading on my mpg now w/ the larger tires.... (obviously my speedo is off too - source of the problem too).

Anyway, before I ramble off to the deep end, you're okay! Need not worry. We all have that problem! - Almost all vehicles have that problem. Best way, don't reset your mpg and over time it'll settle and get closer to your actual mpg.... (when i dunno) :pat:

jharris2

Oddly, I've had it read low when on a long all-highway drive -- since it uses an average, the average from last reset was mostly city driving.

Most of the time, though, it's running about the same error as you. Don't worry about it -- just switch the eye candy to the distance to empty (DTE) mode -- it's closer to accurate and more useful anyway.

EDGE

Yup same thing here, my old man think it gets excellent gas mileage

bulldog-yota

Thanx guys, it seems Toyota took the cheap route in gas milage calculation/computer or just wanted it to look good

My BMW was always spot on in total fuel consumption.

At least the DTE is pretty accurate

EricM

Gosh, I wish mine got the 17-18mpg that bulldog is getting. My V8 Sport ranges from 14 to 16mpg (the display always reads about 2mpg higher than actual). It's the first vehicle I've ever owned that consistently gets less than the EPA mileage rating...

I'm wondering if there's something wrong with mine. I don't think it has much to do with the way I drive... my 02 GMC Z-71 pickup with a 5.3L V-8 and 3.73 rear consistently gets 16-17 in town and about 21mpg on the road (on regular fuel I might add vs. the premium that's "recommended" for the Toyota). Both numbers are better than the EPA ratings and I drive it exactly the same route and manner as I drive the Toyota.

What kind of real world mileage are you other 4th gen V8 owners getting?

dcampen

Same here. On my second tank of gas in my new 4Runner it was all free flowing highway driving at 65-75 mph and I got 16.2 mpg while the display read 18 mpg.

bulldog-yota

Are you guys using premium gas?

I get 15-16 in town only, 17-18 mix of town and highway, and if i do 75 on the highway I get 20-21. This is the measured gas mileage, the indicator showed 2-3mpg more, so I initially thought I got 23-24 mpg on the highway. Thats why I chechked.

My odo and speedo is accurate, measured with my GPS. Maybe your odo is under reading?? DO you still have the stock tyres?

Good Times

Using 87 octane to save $$. Figure 91 didn't do much for me so there's really no need for it. Now unless you're SC'd out, I'd say run the 87 as you'll be fine!

My speedo runs low cuz of the 285's I'm rolling on. Btw the truck did lose some of it's zip due to the larger tires... Kinda bummed but it's really minor that I don't mind.

bulldog-yota

I use premium, maybe it gives better mileage if I look at what the other guys are getting. So it might be worth the extra $$ you pay per gallon as it gives more miles???

One of the reasons I got the 4Runner was that it had a lot of zip with the V8 and the 5spd Auto was silky smooth. A lot better than any of the competition!!

EricM

Yeah, I've been using premium... that's all I use. Hopefully it will improve once I get more miles on it. I've got 6K on it now. I think MotorWeek said they were averaging 17 on theirs by the end of their year long test.

jharris2

One way to tell is to run a few tankfuls of regular and of premium and measure the results. Generally, I find that premium gives so little mileage benefit that it is not worth the price difference. Of course, YMMV.

niseguy

I think I am getting 14-16 for the city and 17-19 for highway.

If I get it into a spreadsheet I'll put more accurate number here...

BTW, my mileage indicator is about 2-3mpg high.

Biff

Yup, I get it.

Biff

I use premium, but the only reason I do is cuz I have and s/c. I was using regular before and I was getting about avg. 17. IMO premium doesn't do much or effect much of the gas mileage.

tank_bmb

I know this is an old post, but why doesnt Toyota just program the MPG reading to show 90% of what it currently shows? It would be a lot more accurate most of the time !

EricM

I don't think it's necessarily a matter of programming it (although the error does seem fairly consistent amongst the posters on this forum). It's a matter of the system they use to calculate it... vehicles that have accurate fuel economy readouts make use of a fuel meter to actually measure the flow of fuel into the engine compared to the distance driven (note that those systems always have an "Instantaneous MPG" readout) whereas the 4Runner simply compares the signal from the fuel gage sending unit vs. miles driven (it's in the factory service manual).

tank_bmb

I realize it's a limitation on how it is calculated, but from every calculation I have ever done on actual versus what the computer reads, it is always about 10% too high. and as you mention most people who have posted on this issue seem to have similar results. Taking that into to consideration, if they programmed it to take 90% of the current value it would be fairly accurate (probably not all the time, but more often than not)

scharged03

I'm getting around 11 mpg mixed driving, premium fuel, of course. Meter reads 18 mpg. I'm getting 265 miles per tank.

Pitchar