Degregation in gas mileage
01-13-17, 01:10 PM
#1
Driver
Thread Starter
Degregation in gas mileage
I've owned my 2010 RX AWD since 2012. While I'm less than impressed with the gas mileage overall at least it was reasonably consistent.
Then a few months ago I notice the mileage got significantly worse.
Doing the same commute I've always done I'm seeing maybe a 10%-15% reduction.
Around here they reformulate the gas in November (I think) and I normally see a reduction but what I'm getting recently is still 10%-15% less than that.
Even on the highway I can't seem to get over 20 MPG.
The car seems to run fine otherwise and I'm using the same 93 octane gas from the same station I've always used.
I put new tires on but I doubt they could make that big of a difference. Tires are inflated properly.
Any thoughts?
Then a few months ago I notice the mileage got significantly worse.
Doing the same commute I've always done I'm seeing maybe a 10%-15% reduction.
Around here they reformulate the gas in November (I think) and I normally see a reduction but what I'm getting recently is still 10%-15% less than that.
Even on the highway I can't seem to get over 20 MPG.
The car seems to run fine otherwise and I'm using the same 93 octane gas from the same station I've always used.
I put new tires on but I doubt they could make that big of a difference. Tires are inflated properly.
Any thoughts?
01-13-17, 01:14 PM
#2
Instructor
The winter reformulation always messes up my mpg along with lower tire pressure due to colder temps. Please write your Congress Person to get rid of the ethanol requirement. We can and need to support our domestic (U.S.) oil drillers while supporting our farmers. Mandatory corn oil is not the way.
01-13-17, 08:56 PM
#4
Pole Position
Trending Topics
01-16-17, 09:33 AM
#8
[QUOTE=ejm3;9736590]I've owned my 2010 RX AWD since 2012. While I'm less than impressed with the gas mileage overall at least it was reasonably consistent.
Then a few months ago I notice the mileage got significantly worse.
Doing the same commute I've always done I'm seeing maybe a 10%-15% reduction.
The car seems to run fine otherwise and I'm using the same 93 octane gas from the same station I've always used.
I put new tires on but I doubt they could make that big of a difference. Tires are inflated properly.
New tires are making the difference, and possibly a tune issue, or other variable. Often, the ECM in the vehicle can make adjustments to compensate for a bad state of tune, and the car will feel and sound okay, but is not as efficient as when properly tuned. I am betting on tires, though. Tell us exactly what tires, brand, model, and size, please.
Then a few months ago I notice the mileage got significantly worse.
Doing the same commute I've always done I'm seeing maybe a 10%-15% reduction.
The car seems to run fine otherwise and I'm using the same 93 octane gas from the same station I've always used.
I put new tires on but I doubt they could make that big of a difference. Tires are inflated properly.
New tires are making the difference, and possibly a tune issue, or other variable. Often, the ECM in the vehicle can make adjustments to compensate for a bad state of tune, and the car will feel and sound okay, but is not as efficient as when properly tuned. I am betting on tires, though. Tell us exactly what tires, brand, model, and size, please.
01-16-17, 11:38 AM
#9
Pole Position
Last week I filed up at my local Costco gas station. I got only 22 mpg on highway. Then I filled up at a Love's truck stop. Coming back on I5 the same route in central CA got 33 mpg . Both fill ups were with regular gas. I think Costco gas is not any good. Now I'm back home driving in mixed city and highway and I'm getting around 35mpg. Usually in mixed driving I get around 40 mpg.
This is on my CT200h, BTW.
IDK if this winter blend gas did this? When did the winter gas started? My tires and other variables are the same with no changes.
[QUOTE=11bravo;9738967]
New tires are making the difference, and possibly a tune issue, or other variable. Often, the ECM in the vehicle can make adjustments to compensate for a bad state of tune, and the car will feel and sound okay, but is not as efficient as when properly tuned. I am betting on tires, though. Tell us exactly what tires, brand, model, and size, please.
This is on my CT200h, BTW.
IDK if this winter blend gas did this? When did the winter gas started? My tires and other variables are the same with no changes.
[QUOTE=11bravo;9738967]
I've owned my 2010 RX AWD since 2012. While I'm less than impressed with the gas mileage overall at least it was reasonably consistent.
Then a few months ago I notice the mileage got significantly worse.
Doing the same commute I've always done I'm seeing maybe a 10%-15% reduction.
The car seems to run fine otherwise and I'm using the same 93 octane gas from the same station I've always used.
I put new tires on but I doubt they could make that big of a difference. Tires are inflated properly.
Then a few months ago I notice the mileage got significantly worse.
Doing the same commute I've always done I'm seeing maybe a 10%-15% reduction.
The car seems to run fine otherwise and I'm using the same 93 octane gas from the same station I've always used.
I put new tires on but I doubt they could make that big of a difference. Tires are inflated properly.
New tires are making the difference, and possibly a tune issue, or other variable. Often, the ECM in the vehicle can make adjustments to compensate for a bad state of tune, and the car will feel and sound okay, but is not as efficient as when properly tuned. I am betting on tires, though. Tell us exactly what tires, brand, model, and size, please.
Last edited by lexusrus; 01-16-17 at 02:01 PM.
01-16-17, 11:54 AM
#10
[QUOTE=lexusrus;9739126]Last week I filed up at my local Costco gas station. I got only 22 mpg on highway. Then I filled up at a Love's truck stop. Coming back on I5 the same route in central CA got 33 mpg . Both fill ups were with regular gas. I think Costco gas is not any good. Now I'm back home driving in mixed city and highway and I'm getting around 35mpg. Usually in mixed driving I get around 40 mpg.
Sir, you did not indicate that you are driving a Prius. You must be, because there is not an RX350 in the world that gets 40MPG. And, the only way you could go from 22mpg on one leg of a trip to 33 on the return is if the first was all uphill, and the return was all downhill. Surely you realize that your numbers are an absolute impossibility, correct?
A simple change in fuel cannot account for 11MPG, all other things being equal. Costco fuel is Top Tier, equal to the best anyone else sells. You really need to figure out how to determine mileage, and what affects mileage. I'm jus' sayin'....
Sir, you did not indicate that you are driving a Prius. You must be, because there is not an RX350 in the world that gets 40MPG. And, the only way you could go from 22mpg on one leg of a trip to 33 on the return is if the first was all uphill, and the return was all downhill. Surely you realize that your numbers are an absolute impossibility, correct?
A simple change in fuel cannot account for 11MPG, all other things being equal. Costco fuel is Top Tier, equal to the best anyone else sells. You really need to figure out how to determine mileage, and what affects mileage. I'm jus' sayin'....
01-16-17, 01:55 PM
#11
Pole Position
AND I'm just saying what I see on the dash readout. Same route no other changes except for different gas statios. This is on my CT200h, BTW.
It was the same route back and forth. To was with Costco fill up. Trip back was the Love Truck Stop fill up.
Incidentally I fly out of LAX a lot and every single shuttle van drivers (Super Shuttle and Prime Time) I asked, they all DO NOT use Costco or Sam's Club gas even though they have access to and cheaper. They seemed to use mostly Chevron, Texaco, Mobil, Shell, and etc. Also they STAY AWAY FROM ARCO AM/PM CRAP.
You said Costco is "TOP TIER" which is true. But did you know ARCO AM/PM also HAS "TOP TIER" designation? But ARCO is crap BC every time I put in ARCO gas, even premium, I get bad mileage and just not very smooth driving.
So to me "TOP TIER" IS JUST SOME MARKETING SCAM.
Just saying.
[QUOTE=11bravo;9739147]
It was the same route back and forth. To was with Costco fill up. Trip back was the Love Truck Stop fill up.
Incidentally I fly out of LAX a lot and every single shuttle van drivers (Super Shuttle and Prime Time) I asked, they all DO NOT use Costco or Sam's Club gas even though they have access to and cheaper. They seemed to use mostly Chevron, Texaco, Mobil, Shell, and etc. Also they STAY AWAY FROM ARCO AM/PM CRAP.
You said Costco is "TOP TIER" which is true. But did you know ARCO AM/PM also HAS "TOP TIER" designation? But ARCO is crap BC every time I put in ARCO gas, even premium, I get bad mileage and just not very smooth driving.
So to me "TOP TIER" IS JUST SOME MARKETING SCAM.
Just saying.
[QUOTE=11bravo;9739147]
Last week I filed up at my local Costco gas station. I got only 22 mpg on highway. Then I filled up at a Love's truck stop. Coming back on I5 the same route in central CA got 33 mpg . Both fill ups were with regular gas. I think Costco gas is not any good. Now I'm back home driving in mixed city and highway and I'm getting around 35mpg. Usually in mixed driving I get around 40 mpg.
Sir, you did not indicate that you are driving a Prius. You must be, because there is not an RX350 in the world that gets 40MPG. And, the only way you could go from 22mpg on one leg of a trip to 33 on the return is if the first was all uphill, and the return was all downhill. Surely you realize that your numbers are an absolute impossibility, correct?
A simple change in fuel cannot account for 11MPG, all other things being equal. Costco fuel is Top Tier, equal to the best anyone else sells. You really need to figure out how to determine mileage, and what affects mileage. I'm jus' sayin'....
Sir, you did not indicate that you are driving a Prius. You must be, because there is not an RX350 in the world that gets 40MPG. And, the only way you could go from 22mpg on one leg of a trip to 33 on the return is if the first was all uphill, and the return was all downhill. Surely you realize that your numbers are an absolute impossibility, correct?
A simple change in fuel cannot account for 11MPG, all other things being equal. Costco fuel is Top Tier, equal to the best anyone else sells. You really need to figure out how to determine mileage, and what affects mileage. I'm jus' sayin'....
Last edited by lexusrus; 01-16-17 at 02:12 PM.
01-16-17, 02:03 PM
#12
My mistake for thinking I was on the RX forum. Whatever gas makes you happy, fine with me.
Our RX 350 gets pretty much the same mileage whether it is Costco, Sams Club, Arco, or Chevron. Tried 'em all, now buy mostly Costco.
Our RX 350 gets pretty much the same mileage whether it is Costco, Sams Club, Arco, or Chevron. Tried 'em all, now buy mostly Costco.
01-16-17, 02:22 PM
#13
Pole Position
I also apologize for not making it clear on my first posting I was driving my CT200h, not my other RX450h.
It's just I find it interesting most, if not ALL Shuttle van drivers DO NOT go to Costco, Sam's Club, or ARCO. I have not seen any of the Super Shuttle or Prime Time Shuttle gas up at Costco, Sam's Club, or ARCO. It would sure be "cheaper" for them. I know a lot of them run CNG. But there are some nonconverted at SAN airport running regular gas. Same thing with all those Prius taxis at LAX.
It's just I find it interesting most, if not ALL Shuttle van drivers DO NOT go to Costco, Sam's Club, or ARCO. I have not seen any of the Super Shuttle or Prime Time Shuttle gas up at Costco, Sam's Club, or ARCO. It would sure be "cheaper" for them. I know a lot of them run CNG. But there are some nonconverted at SAN airport running regular gas. Same thing with all those Prius taxis at LAX.
01-16-17, 03:49 PM
#14
There is a lot of talk on numerous auto forums about "top tier" gas. Many folks think it is a marketing gimmick which a maker of fuels can purchase a license for use. It is much more than that, however. Certainly anytime you own the rights to a superior grade product, it will be marketed. We all have to decide for ourselves what is "gimmick", and what is the real thing.
Top Tier Detergent Gasoline is a performance specification and trademark designed and supported by several major automakers — BMW, General Motors, Fiat Chrysler Automobiles, Honda, Toyota, Volkswagen, Mercedes-Benz, and Audi (as of 2017). Top Tier gasolines must maintain levels of detergent additives that result in a higher standard of engine cleanliness and performance as compared to the EPA requirement. In addition, Top Tier fuels may not contain metallic additives, which can harm the vehicle emission system and create pollutants. Fuels which qualify for Top Tier status mush achieve the higher requirements in every grade of gasoline produced. Resultantly, no vendor selling Top Tier fuel can only have Top Tier Premium...all grades must qualify under the TTDA guidelines.
Independent studies by AAA and Consumer Reports found that gas labeled "Top Tier" had significantly higher levels of beneficial additives, sufficient enough for both to consider the generally higher price of TT fuel to be worth it for longer engine life, and overall better performance.
I don't advocate any brand of gas over another. Since Costco and ARCO are both Top Tier, and both far cheaper than other leading brands, I use them regularly. I won't disagree with anyone else's feelings, or results. We must decide for ourselves.
Top Tier Detergent Gasoline is a performance specification and trademark designed and supported by several major automakers — BMW, General Motors, Fiat Chrysler Automobiles, Honda, Toyota, Volkswagen, Mercedes-Benz, and Audi (as of 2017). Top Tier gasolines must maintain levels of detergent additives that result in a higher standard of engine cleanliness and performance as compared to the EPA requirement. In addition, Top Tier fuels may not contain metallic additives, which can harm the vehicle emission system and create pollutants. Fuels which qualify for Top Tier status mush achieve the higher requirements in every grade of gasoline produced. Resultantly, no vendor selling Top Tier fuel can only have Top Tier Premium...all grades must qualify under the TTDA guidelines.
Independent studies by AAA and Consumer Reports found that gas labeled "Top Tier" had significantly higher levels of beneficial additives, sufficient enough for both to consider the generally higher price of TT fuel to be worth it for longer engine life, and overall better performance.
I don't advocate any brand of gas over another. Since Costco and ARCO are both Top Tier, and both far cheaper than other leading brands, I use them regularly. I won't disagree with anyone else's feelings, or results. We must decide for ourselves.
01-16-17, 04:02 PM
#15
Pole Position
I see what you are saying.
Question:. Are there different grades within "top tier" gas brands? Who had done "controlled double blind" studies (if even possible?) and see if there are any differences WITHIN "top tier" gas brands (especially mpg differences within the same octane level across different gas brands)?
Question:. Are there different grades within "top tier" gas brands? Who had done "controlled double blind" studies (if even possible?) and see if there are any differences WITHIN "top tier" gas brands (especially mpg differences within the same octane level across different gas brands)?
There is a lot of talk on numerous auto forums about "top tier" gas. Many folks think it is a marketing gimmick which a maker of fuels can purchase a license for use. It is much more than that, however. Certainly anytime you own the rights to a superior grade product, it will be marketed. We all have to decide for ourselves what is "gimmick", and what is the real thing.
Top Tier Detergent Gasoline is a performance specification and trademark designed and supported by several major automakers — BMW, General Motors, Fiat Chrysler Automobiles, Honda, Toyota, Volkswagen, Mercedes-Benz, and Audi (as of 2017). Top Tier gasolines must maintain levels of detergent additives that result in a higher standard of engine cleanliness and performance as compared to the EPA requirement. In addition, Top Tier fuels may not contain metallic additives, which can harm the vehicle emission system and create pollutants. Fuels which qualify for Top Tier status mush achieve the higher requirements in every grade of gasoline produced. Resultantly, no vendor selling Top Tier fuel can only have Top Tier Premium...all grades must qualify under the TTDA guidelines.
Independent studies by AAA and Consumer Reports found that gas labeled "Top Tier" had significantly higher levels of beneficial additives, sufficient enough for both to consider the generally higher price of TT fuel to be worth it for longer engine life, and overall better performance.
I don't advocate any brand of gas over another. Since Costco and ARCO are both Top Tier, and both far cheaper than other leading brands, I use them regularly. I won't disagree with anyone else's feelings, or results. We must decide for ourselves.
Top Tier Detergent Gasoline is a performance specification and trademark designed and supported by several major automakers — BMW, General Motors, Fiat Chrysler Automobiles, Honda, Toyota, Volkswagen, Mercedes-Benz, and Audi (as of 2017). Top Tier gasolines must maintain levels of detergent additives that result in a higher standard of engine cleanliness and performance as compared to the EPA requirement. In addition, Top Tier fuels may not contain metallic additives, which can harm the vehicle emission system and create pollutants. Fuels which qualify for Top Tier status mush achieve the higher requirements in every grade of gasoline produced. Resultantly, no vendor selling Top Tier fuel can only have Top Tier Premium...all grades must qualify under the TTDA guidelines.
Independent studies by AAA and Consumer Reports found that gas labeled "Top Tier" had significantly higher levels of beneficial additives, sufficient enough for both to consider the generally higher price of TT fuel to be worth it for longer engine life, and overall better performance.
I don't advocate any brand of gas over another. Since Costco and ARCO are both Top Tier, and both far cheaper than other leading brands, I use them regularly. I won't disagree with anyone else's feelings, or results. We must decide for ourselves.