ES350 gasoline
#31
I went back and looked at the owners manual and it states that it recalculates when the gas cap is opened. I am in TX, BTW. However, I probably will still use the old fashioned way of doing mileage. Wife and I are pretty strict about that.
#32
I've always speculated on how the car computers calculate the fuel economy. I have not done a search nor do I have firsthand knowledge but I think it probably does it by counting the number of times each injector opens and the duration it was open. I seriously doubt there is any sort of flow meter that measures the exact volume of fuel consumed. But I suspect that you can determine how much fuel was consumed with pretty high accuracy by looking at injector cycles. Due to the precise metering of fuel required for an efficient combustion cycle, the need for a consistent fuel pressure, the injector open time would give the best number of volume of fuel used. Having said that, the lie-o-meters on my 2011 Sonata was always high by a good 2 mpg and the ES350 seems to be high by about 1 mpg, when compared to calculating my mpg manually.
However, if it did as you say and used the injector cycles, it would be much more accurate. Problem is every car would need a Terabyte HDD just to store that amount of info
#33
It doesn't need the injector cycle, the fuel pump is a fixed volume (i.e. gallons/liters per hour). It then guesses based upon how many 'hours' the car has run for and how many miles you've gone. That's why they're inaccurate.
However, if it did as you say and used the injector cycles, it would be much more accurate. Problem is every car would need a Terabyte HDD just to store that amount of info
However, if it did as you say and used the injector cycles, it would be much more accurate. Problem is every car would need a Terabyte HDD just to store that amount of info
For example - and this is just a made up example, I don't really know how much fuel our injectors use. Let's say we have an 8gph fuel pump. If each injector had the ability to use a gallon of fuel per hour when on constantly, you'd use 6 gallons an hour. But at 1/6 duty, the engine would use only one gallon per hour, not the 8 gph that the fuel pump could provide.
#34
Alright, so yesterday I broke down and decided to put in regular gas So far I can tell two things: 1) the throttle response is not as quick as before (could be my butt-dyno inaccuracy) and 2) fuel consumption didn't change (based on the car computer - will confirm on the next fill up). I will do a few more tanks just to make sure that the long term fuel trim is adjusted to the new octane (ign angle). As for response, I'll just step on it harder
#35
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I'm certainly going to try regular at the next fill-up just out of curiosity to see if I can tell a difference with response, fuel economy or pre-ignition. My last 3 vehicles ('98 Honda Accord, '99 Toyota Land Cruiser, '11 Hyundai Sonata) have all had pre-ignition/pinging under heavy load when I put the regular in it. I live at 5,000 ft elevation so our Octane numbers are 86, 88 and 90/91. I've just decided that I'm willing to pay the extra $3 - $4 for the premium per gas tank and not have to worry about the pre-ignition/pinging. That's less than the cost of a Subway sandwich to ensure I'm getting the most efficient burn and no detectable pre-ignition.
#36
Yeah, in your situation due to elevation I would do the same. My former Nissan Maxima would also ping with anything less than 91 octanes and I am at sea level. I pushed the ES a bit yesterday under WOT to see if it would ping and it didn't. I am yet to go up a steep hill under WOT, that's where Maxima would ping with low octane, to see if ES would...
Btw, yesterday savings for me were 60 liters x $0.14 = $8.40. The difference from regular to premium here is $0.13-0.17 per liter, i.e. avg 12% mark up over regular so is significant. Works out to about $400 in savings per year based on current gas prices and 30,000 km/year of driving at 9L/100km rate. I know that in US the % difference is much smaller between prem and reg...
Btw, yesterday savings for me were 60 liters x $0.14 = $8.40. The difference from regular to premium here is $0.13-0.17 per liter, i.e. avg 12% mark up over regular so is significant. Works out to about $400 in savings per year based on current gas prices and 30,000 km/year of driving at 9L/100km rate. I know that in US the % difference is much smaller between prem and reg...
#38
#39
Well my cars been off the lot for awhile now and I'm up to 18.5 on my 2010. Like I said both 2010s on the lot said the cars were averaging 13.5 mpg and since the cars idle on the lot alot that may say something about how the computers operate. Then again people tend to floor the car when they it and I would imagine the computer would compensate for when you're moving. The manual says premium is "required" not recommended.
For those who say it's pennies a day, it really isn't. Where I'm at it's a 45 cent a gallon difference. Do the math..
Is the '10 engine the same as on the Camry or was that just 2007 - 2009?
Also is 18.5 "computer mpg" similar to what you all are getting?
Thanks
For those who say it's pennies a day, it really isn't. Where I'm at it's a 45 cent a gallon difference. Do the math..
Is the '10 engine the same as on the Camry or was that just 2007 - 2009?
Also is 18.5 "computer mpg" similar to what you all are getting?
Thanks
Last edited by rickster9; 01-13-14 at 05:09 PM.
#40
What about Mid-grade or 89 oct? Would that be a compromise? FYI, when I was in CO this summer in my 05 DeVille, I did put premium in it even I normally put in regular. It has the Northstar V8. I felt that going over the "million dollar highway" from Durango to Silverton and Ouray, it was worth it. Got great milage too for a V8
#41
Lexus Champion
Well my cars been off the lot for awhile now and I'm up to 18.5 on my 2010. Like I said both 2010s on the lot said the cars were averaging 13.5 mpg and since the cars idle on the lot alot that may say something about how the computers operate. Then again people tend to floor the car when they it and I would imagine the computer would compensate for when you're moving. The manual says premium is "required" not recommended.
For those who say it's pennies a day, it really isn't. Where I'm at it's a 45 cent a gallon difference. Do the math..
Is the '10 engine the same as on the Camry or was that just 2007 - 2009?
Also is 18.5 "computer mpg" similar to what you all are getting?
Thanks
For those who say it's pennies a day, it really isn't. Where I'm at it's a 45 cent a gallon difference. Do the math..
Is the '10 engine the same as on the Camry or was that just 2007 - 2009?
Also is 18.5 "computer mpg" similar to what you all are getting?
Thanks
#42
Yes, it really is. You shouldn't be letting the car go below a quarter tank. In my 07, to fill from a quarter tank takes about 15 gallons.
15 * .45 = $6.75 per tank.
Then it becomes a question of how long a tank lasts you? Personally, I can go about 10 days on a tank. That makes it 67.5 cents per day, if I was to use premium (91 or 93) which I don't.
I use 89 octane and the car distinctly runs better. 89 octane is about 15 cents per gallon more than 87 where I live.
15 * .15 = $2.25 per tank. Divide that by the 10 days I get out of a tank, and it's 22 cents a day to have my car run smoother and quieter, get (slightly) better MPG and be more responsive.
#43
Exactly my point JCat. Even under worse case scenario, like Rickster, where it's $0.45 a gallon more; A totally empty tank would only be $8.00 more. And as you correctly pointed out, if a FULL tank lasts 10 days, that's still only $0.80 a day.
But what really matters is: "How does the car handle the higher grade gasoline"? If it doesn't sound better, drive better, better MPG, etc... then it's totally silly to pay the extra $8.00 per tank. But if the car improves in ANY manner at all, then that $8.00 per tank will almost vanish. This is where people don't understand economics. JUST 1 MPG IMPROVEMENT makes a major difference. Using the average of 20 MPG in town; 18 gallons is 360 miles. 1 MPG improvement means 378 miles. 17 miles more. Which is almost an entire gallon of gasoline for FREE. Meaning, you just saved around $3.00. So now, that $8.00 additional cost per tank, just dropped down to $5.00 per tank. And common sense says; if your engine improves on the MPG efficiency, then chances are that the MILE MARK when an expensive significant repair will be required, will be pushed out longer. In other words, less wear and tear on the engine and tranny. And chances are, if you improve just 1mpg in town, that you'll probably improve a little more than that if you drive on the open road.
But again, I always say that each person needs to drive their car for at least 2 tank full in a row of EACH GRADE gasoline. Your car will let you know which one it likes. If it runs equally on 87 and 89 grade and no difference at 91, then use the 87. But if it gets the best MPG and runs the smoothest on the 89 or 91, then that is what you should use. Any extra cost will be negated with MPG and repairs later.
But what really matters is: "How does the car handle the higher grade gasoline"? If it doesn't sound better, drive better, better MPG, etc... then it's totally silly to pay the extra $8.00 per tank. But if the car improves in ANY manner at all, then that $8.00 per tank will almost vanish. This is where people don't understand economics. JUST 1 MPG IMPROVEMENT makes a major difference. Using the average of 20 MPG in town; 18 gallons is 360 miles. 1 MPG improvement means 378 miles. 17 miles more. Which is almost an entire gallon of gasoline for FREE. Meaning, you just saved around $3.00. So now, that $8.00 additional cost per tank, just dropped down to $5.00 per tank. And common sense says; if your engine improves on the MPG efficiency, then chances are that the MILE MARK when an expensive significant repair will be required, will be pushed out longer. In other words, less wear and tear on the engine and tranny. And chances are, if you improve just 1mpg in town, that you'll probably improve a little more than that if you drive on the open road.
But again, I always say that each person needs to drive their car for at least 2 tank full in a row of EACH GRADE gasoline. Your car will let you know which one it likes. If it runs equally on 87 and 89 grade and no difference at 91, then use the 87. But if it gets the best MPG and runs the smoothest on the 89 or 91, then that is what you should use. Any extra cost will be negated with MPG and repairs later.
#44
When I lived 7 miles (city) from work, my mileage was about that. Now that I'm 17 miles away in a more sub-urban setting (i.e. getting up to higher speed and being able to hold that speed) I see anywhere from a low of 22 (remote starts and idling kills mileage in winter) and a high of 27.