Gas capacity and mileage questions

[motordavid]

Quote:
Originally Posted by motordavid
Doing the arith of miles driven divided by gallons over those same tanks full will give a more real world mpg, for those specific tanks full. The real number and the OBC may be close, or not.

Originally Posted by sunny5280

I'm not sure I agree with this. This method of calculation assumes the amount of fuel you're adding to the tank is the same amount of fuel consumed. There's no way to be certain it is and, I suspect, it's not.

I spent a fair amount of time trying to get the computer to match the hand calculations. And I was never able to do so when calculating MPG between fill-ups. Over time the two came closer together. I suspect that's because the average eliminates the variances.

No arm wrestle here...I think I said all 'that' in my orig post...the variables are many, and difficult to repeat the exact method(s) with every fill up.

My points to the OP were and are: the OBC mpg reading is 'close', though often not identical, for many reasons.

Watching the mpg readout at any given time is fun but not an actual mpg reading, whether it be instant or cumulative; it is a ball park.

The regular focus here on mpg vis a vis "I get this" or "I got that" is all anecdtoal and at best a personal observation or anecdotal...but for anyone to get a reasonable value of thier mpg, it takes several tanks over similar driving conditions, and simple arithmetic. All that is academic, as few of us drive the same style, over the same route, over several tanks full, and if we do, then that sample is reasonable for that period/route(s). Add in the vagaries of different climate conditions, fuel blends, et al, and it is simply a 'ballpark' and info for that user.

The focus on mpg with these various models of 2 1/2 ton cars is amusing, but none of us are going to win mpg contests.

YMMV...
GL, mD

[sunny5280]

Originally Posted by motordavid

Quote:
Originally Posted by motordavid
Doing the arith of miles driven divided by gallons over those same tanks full will give a more real world mpg, for those specific tanks full. The real number and the OBC may be close, or not.



No arm wrestle here...I think I said all 'that' in my orig post...the variables are many, and difficult to repeat the exact method(s) with every fill up.

My points to the OP were and are: the OBC mpg reading is 'close', though often not identical, for many reasons.

Watching the mpg readout at any given time is fun but not an actual mpg reading, whether it be instant or cumulative; it is a ball park.

The regular focus here on mpg vis a vis "I get this" or "I got that" is all anecdtoal and at best a personal observation or anecdotal...but for anyone to get a reasonable value of thier mpg, it takes several tanks over similar driving conditions, and simple arithmetic. All that is academic, as few of us drive the same style, over the same route, over several tanks full, and if we do, then that sample is reasonable for that period/route(s). Add in the vagaries of different climate conditions, fuel blends, et al, and it is simply a 'ballpark' and info for that user.

The focus on mpg with these various models of 2 1/2 ton cars is amusing, but none of us are going to win mpg contests.

YMMV...
GL, mD

IMO it's all just academic discussion anyway. No matter what the computer / hand calculations say we get the fuel mileage we get.

[e30cabrio]

My main concerns are is the mileage indicitave of any possible issue (no), did I run the tank to fumes (no), is the display wildly off (yes) is there a solution (possibly)

I appreciate the input.

[sunny5280]

Originally Posted by e30cabrio

My main concerns are is the mileage indicitave of any possible issue (no), did I run the tank to fumes (no), is the display wildly off (yes) is there a solution (possibly)

I appreciate the input.

My parents track their mileage at every fill-up for just this reason. I think which method one uses to track it is less important than using the same method to track it.

[TerminatorX5]

Originally Posted by e30cabrio

My main concerns are is the mileage indicitave of any possible issue (no), did I run the tank to fumes (no), is the display wildly off (yes) is there a solution (possibly)

I appreciate the input.

gee, i am geting soo confused between the MPG threads that are going on at this time that i don't remember where i posted what!!!

anyways, i noticed that my MPG increased for better within last few fill-ups... the method i am using is, record the quantity of fuel going into tank, record quantity of miles driven... devide the miles by gallon, get MPG as a result... since I have been doing this since the day one i got the truck in my posession, i have worked out the unknown factor of the initial fill-up and the mileage that was on the truck, and already averaged out over the course of last year... i suspect that more-than-often oil changes may have contributed to the improvement of the MPG - I went from the BMW oil changes at a dealer at indicator dictate oil changes with BMW 5-30 oil to self-changes using Castrol synthetic 5-40 oil and using liqui-molly engine flush before the oil change (had done twice so far) and also dumping the AUTO-RX into the oil (done twice as well), and the interval for last several changes was 5000 to 6000 miles...
also, the CCV membranes were changed...

I have 2006 4.8iS, i have put about 30K miles in the last year, now at about 97K miles

[Ricky Bobby]

Originally Posted by TerminatorX5

gee, i am geting soo confused between the MPG threads that are going on at this time that i don't remember where i posted what!!!

anyways, i noticed that my MPG increased for better within last few fill-ups... the method i am using is, record the quantity of fuel going into tank, record quantity of miles driven... devide the miles by gallon, get MPG as a result... since I have been doing this since the day one i got the truck in my posession, i have worked out the unknown factor of the initial fill-up and the mileage that was on the truck, and already averaged out over the course of last year... i suspect that more-than-often oil changes may have contributed to the improvement of the MPG - I went from the BMW oil changes at a dealer at indicator dictate oil changes with BMW 5-30 oil to self-changes using Castrol synthetic 5-40 oil and using liqui-molly engine flush before the oil change (had done twice so far) and also dumping the AUTO-RX into the oil (done twice as well), and the interval for last several changes was 5000 to 6000 miles...
also, the CCV membranes were changed...

I have 2006 4.8iS, i have put about 30K miles in the last year, now at about 97K miles

x2 T, times must really be tough out there to be tracking mileage as much as the E53 forum has been lately! Maybe UCrew should rename us the Xoutpost/Prius partnership forum lol!


I haven't really paid much attention to complete logging of mileage, however, I reset the trip meter each fillup so I have an approximation of how many miles I can expect to get out of a tank. If I suddenly start getting significantly less miles out of the tank I know I need a tune up or something similar, but for the most part my mileage is steady. Lifetime Consumption on the OBC shows 18.2 mpg which is about consistent with what I get with mixed driving (the manual transmission helps the mileage considerably). If its a full tank of highway driving, I may get 21 mpg or more on that tank.

[motordavid]

Originally Posted by sunny5280

IMO it's all just academic discussion anyway. No matter what the computer / hand calculations say we get the fuel mileage we get.

...

[motordavid]

Originally Posted by sunny5280

IMO it's all just academic discussion anyway. No matter what the computer / hand calculations say we get the fuel mileage we get.

...

I wonder if the Prius/ChevyCruzeDiesel/JettaDiesel gang is over on their boards posting about great handling, built like a brick, fun to drive, etc.?

[TerminatorX5]

Originally Posted by motordavid

...

I wonder if the Prius/ChevyCruzeDiesel/JettaDiesel gang is over on their boards posting about great handling, built like a brick, fun to drive, etc.?

I must agree - it is built like a brick!!!

[TiAgX5]

I've seen almost 26 gals on numerous fills (and I add 10 to 11 oz of Lucas Upper Cyl Lube before EVERY fill, ethanol SUCKS!!!), at different stations everywhere from Florida to New Mexico, last one was on 8-20 in Coppell, TX..........and the pump stopped at $90 because that is the max the station clears a credit card for, it was still filling.........