Broke 50 MPG

[STC]

Hi Everyone,

Yesterday, I was able to make 50+ MPG on my tank for the third time in a row! I just broke the 50 mile mark this time... 50.727 MPG.

The driving technique, speed, tire pressure, weight, outside temperatures, and fuel (non-ethanol & same gas pump) were all the same. The only difference being the highway distance. This time I took two trips of 200 and 150 miles, instead of the last time being two trips of 200 and 100 miles. Yet, I traveled more trip highway miles on this tank and got less MPG of about 1.5 MPG? I can only think this small difference was that I may have used the A/C a little more than the last time? And the extra driving distance was more flat? I could not glide as much.

Any rate, I would love to make four consecutive 50+ MPG on the tank. Unfortunately, I believe this will be highly unlikely! I’m not taking any road trips soon and will actually be driving through campus all the time when Penn State starts classes in less than two weeks... that will be interesting!
It is still hard for me to believe that the initial fuel fill-up was only 28 MPG. This is why breaking 50 mile mark has been a challenge for me with the Yaris and somewhat an obsession... LOL!

I must say, the Yaris is an incredible car for FE! No doubt... I’m very happy with my decision on the purchase now...

I will soon be purchasing the Ecometer from MI... Can’t wait to see the values it shows during my driving...

Cheers!

Gas Tank mile increments (non-ethanol gas used):
1st Bar drop (8/8) > 116 mi (116)
2nd Bar drop (7/8) > 71 mi (187)
3rd Bar drop (3/4) > 55 mi (242)
4th Bar drop (5/8) > 75 mi (317)
5th Bar drop (1/2) > 57 mi (374)
6th Bar drop (3/8) > 63 mi (437)
7th Bar drop (1/4) > 65 mi (502)
8th Bar drop (1/8) > 0

Tank total : 502 miles
Fuel used: 9.896 gallons
MPG: 50.727

[bkrownd]

Even in the best conditions I haven't cracked 50. However, the short recessed stem of the Yaris' wheel air valve has kept me from being able to increase my tire pressure above what the dealer put in. My home air pump can't get into that tight space. :/ Someday I will get a new pump...

[nmgolfer]

Congrats mark you're doing great! Give us some specifics.... How did you do it? Ave. Speed? Hilly or Flat? Any mods made to increase FE?

Rick

[nmgolfer]

Originally Posted by bkrownd

Even in the best conditions I haven't cracked 50. However, the short recessed stem of the Yaris' wheel air valve has kept me from being able to increase my tire pressure above what the dealer put in. My home air pump can't get into that tight space. :/ Someday I will get a new pump...

I had to buy a new tire inflater/gauge down at harbor freight $5.00 for the same reason.... no biggy... first couple of tanks will pay for it I figure.. Running 38 in the Bridgestone potenzas at the moment.

[STC]

Originally Posted by nmgolfer

Congrats mark you're doing great! Give us some specifics.... How did you do it? Ave. Speed? Hilly or Flat? Any mods made to increase FE?

Rick

To start with most of my normal driving routine is highway commutes (country roads) going to the limited city driving at work. I average mid to upper forties.

Occasionally, I take work trips around PA along with my normal driving routine. Trips range from 100 to 300 miles and I have taken two trips on one tank several times. The last three times have all been trips to Hershey, Altoona, and Bloomsburg, PA.

Speed and terrain are the basics for good FE. Using in-gear glides (DFCO) and in-gear glides to minimal braking for city lights furthers good FE. I think one of the most important rules for great FE is to apply the accelerator ever so lightly all the time. When I bought my new car, I drove it like my other cars in the past... jack-rabbit starts and heavy braking to a stop. I got 27-28 MPG! I started to take it easy on the accelerator... and it instantly jumped to the mid-thirties. Then I started with my glides and limited brake use that brought me up to the lower forties. There were other techniques that helped in a minimum amount... duration of A/C & heater, no engine start idling, defroster use, and shutting off the engine at drive-thru tellers, etc.

These last trips involved a decent amount of highway hills (hilly terrain) that I was able to use DFCO: http://www.yarisworld.com/forums/showthread.php?t=4248. Due to the hill lengths, I’m able to maintain my momentum speed for a good amount of time due to the grades. When I’m not able to maintain, I pop the gear into neutral and glide. On ramps and slow downs I used DFCO all the time.

I do not have SCII or Ecometer to check my average speed yet. On the highway I travel the limited speed according to State law (15 MPH below specific speed limit)... Interstate around 40-53 MPH and county roads around 40-45 MPH (once you start to go over 55 MPH wind resistance becomes a factor in the Yaris for FE). City driving is up to the posted speed limit. Whether what gear I’m in, while driving my RPM is mostly under 2,200. When I shift, I’m generally shifting just under 2,000 RPM. When driving in fifth gear or under, I only down-shift when the tachometer drops below 1,300 RPM. While driving on my last three trips most was 2,000 RPM or under. Importantly, with shift points I try to be very light on the accelerator. When there is heavy city traffic, I’m still light on the accelerator, but shift fast through the gears to get up to speed so I don’t piss-off other drivers. I try to learn new driving area environments as quick as possible while maintain hypermiling techniques.

No mods to increase FE. I do have an SS exhaust resonated tip mod that probable has little or no negative affect on FE? My tires are considered low resistance tires (LRR), Bridgestone Potenza RE 92 185 x 60-15. I bumped up my PSI to 42 to help in the roll. My travel is light... my work equipment and luggage is around 70lbs. The fuel I use is RBOB gas (non-ethanol)... approximately 1-3 MPG better than ethanol gas. Soon the gas will be leaving this area and I will be forced to use ethanol gas additive.

Does this specific information help?

Cheers!

[jhsouders]

Originally Posted by STC

Both trips I traveled in the late morning into afternoon. The outside temperature was at around 90-92 degrees with high humidity... very sticky. I used A/C over half of the time.

Cheers!

Ever thought about trying a tank without AC to see if you can get that mpg number even higher?

[STC]

Originally Posted by jhsouders

Ever thought about trying a tank without AC to see if you can get that mpg number even higher?

Yes! But, I would rather not sacrifice comfort to achieve possibly a mile or two more?

By using the A/C half the time (incrementaly) does not make much of a difference in FE. I would imagine using it all the time would be pretty much the same case? There are other variables I could concentrate on in driving and possibly squeeze out the 1-2 miles that I would of gained by no A/C.

Right now, I'm comfortable with breaking fifty. I'm sure breaking 55 can be achieved... but to what extent and sacrifice?

Cheers!

[nmgolfer]

Thanks for the reply Mark. Your mileage makes sense at those speeds and highway vs. city percentages along with contentious driving. I'm pleased I got 43.8 in combined city highway on my first tank and I aim to do better on the next.

Yes form drag typically begins to exceed rolling resistance (and other linear loses) at about 55 mpg and rises exponentially. That is why aerodynamic form factor (drag coefficient times frontal area or CdA) is so critically important. Unfortunately its not possible to drive 55 in most places and still go with the flow. Jimmy Carter tried (for this reason... and because it saves lives) but Americans like more speed and have longer distances to travel particularly in the West.

Yaris compares pretty good with CdA at 6.13 as compared to 5.84 for the third Gen Prius. But there is room for improvement. I'd like to see more aerodynamic wheel covers and rear wheel well covers on the next Gen Yaris and if they could make it a low cost plug in hybrid with regen braking that would be even better... then we could use racing discs on front wheels and back.

Originally Posted by STC

To start with most of my normal driving routine is highway commutes (country roads) going to the limited city driving at work. I average mid to upper forties.

Occasionally, I take work trips around PA along with my normal driving routine. Trips range from 100 to 300 miles and I have taken two trips on one tank several times. The last three times have all been trips to Hershey, Altoona, and Bloomsburg, PA.

Speed and terrain are the basics for good FE. Using in-gear glides (DFCO) and in-gear glides to minimal braking for city lights furthers good FE. I think one of the most important rules for great FE is to apply the accelerator ever so lightly all the time. When I bought my new car, I drove it like my other cars in the past... jack-rabbit starts and heavy braking to a stop. I got 27-28 MPG! I started to take it easy on the accelerator... and it instantly jumped to the mid-thirties. Then I started with my glides and limited brake use that brought me up to the lower forties. There were other techniques that helped in a minimum amount... duration of A/C & heater, no engine start idling, defroster use, and shutting off the engine at drive-thru tellers, etc.

These last trips involved a decent amount of highway hills (hilly terrain) that I was able to use DFCO: http://www.yarisworld.com/forums/showthread.php?t=4248. Due to the hill lengths, I’m able to maintain my momentum speed for a good amount of time due to the grades. When I’m not able to maintain, I pop the gear into neutral and glide. On ramps and slow downs I used DFCO all the time.

I do not have SCII or Ecometer to check my average speed yet. On the highway I travel the limited speed according to State law (15 MPH below specific speed limit)... Interstate around 40-53 MPH and county roads around 40-45 MPH (once you start to go over 55 MPH wind resistance becomes a factor in the Yaris for FE). City driving is up to the posted speed limit. Whether what gear I’m in, while driving my RPM is mostly under 2,200. When I shift, I’m generally shifting just under 2,000 RPM. When driving in fifth gear or under, I only down-shift when the tachometer drops below 1,300 RPM. While driving on my last three trips most was 2,000 RPM or under. Importantly, with shift points I try to be very light on the accelerator. When there is heavy city traffic, I’m still light on the accelerator, but shift fast through the gears to get up to speed so I don’t piss-off other drivers. I try to learn new driving area environments as quick as possible while maintain hypermiling techniques.

No mods to increase FE. I do have an SS exhaust resonated tip mod that probable has little or no negative affect on FE? My tires are considered low resistance tires (LRR), Bridgestone Potenza RE 92 185 x 60-15. I bumped up my PSI to 42 to help in the roll. My travel is light... my work equipment and luggage is around 70lbs. The fuel I use is RBOB gas (non-ethanol)... approximately 1-3 MPG better than ethanol gas. Soon the gas will be leaving this area and I will be forced to use ethanol gas additive.

Does this specific information help?

Cheers!

[nmgolfer]

I wish somebody made an after-market swamp cooler for these things. Wouldn't need to run the AC compressor or draw in as much air with the fan (less sinking drag)... Wouldn't work in high humidity climes though.

Originally Posted by STC

Yes! But, I would rather not sacrifice comfort to achieve possibly a mile or two more?

By using the A/C half the time (incrementaly) does not make much of a difference in FE. I would imagine using it all the time would be pretty much the same case? There are other variables I could concentrate on in driving and possibly squeeze out the 1-2 miles that I would of gained by no A/C.

Right now, I'm comfortable with breaking fifty. I'm sure breaking 55 can be achieved... but to what extent and sacrifice?

Cheers!

[STC]

Originally Posted by nmgolfer

Thanks for the reply Mark. Your mileage makes sense at those speeds and highway vs. city percentages along with contentious driving. I'm pleased I got 43.8 in combined city highway on my first tank and I aim to do better on the next.

Yes form drag typically begins to exceed rolling resistance (and other linear loses) at about 55 mpg and rises exponentially. That is why aerodynamic form factor (drag coefficient times frontal area or CdA) is so critically important. Unfortunately its not possible to drive 55 in most places and still go with the flow. Jimmy Carter tried (for this reason... and because it saves lives) but Americans like more speed and have longer distances to travel particularly in the West.

Yaris compares pretty good with CdA at 6.13 as compared to 5.84 for the third Gen Prius. But there is room for improvement. I'd like to see more aerodynamic wheel covers and rear wheel well covers on the next Gen Yaris and if they could make it a low cost plug in hybrid with regen braking that would be even better... then we could use racing discs on front wheels and back.

You’re welcome! 43.8 MPG combined on your first tank is very good. More likely you will do better the next time around. With that first tank, what was your percentage in city vs highway driving and speed? How about terrain? Years back when I was in Albuquerque, New Mexico, I recall on the Interstate some long grades, but not much steepness?

Yes, CdA is non-linear in scale! That is why I keep my speed under 55 MPH. Honda in my eyes has always made cars with good CdA design in mind. Too bad they stopped making the CRX line in the 90’s.... they were great non-hybrid FE cars. What’s up with Honda today? Their 1st Gen Insight was great in CdA numbers!

I’m fortunate that I can drive under 55 MPH. The flow seems like 55-60 in posted 55 MPH zones and 65-75 in 65 MPH zones. People don’t pass me going terribly fast. I’ve gotten a few beeps (3 so far) and a couple of fingers... LOL! Most importantly, I’m not a hazard to others driving safety. We have large Amish communities in Central and Southeast Pennsylvania... most people drive carefully on country roads because of the hills and slow moving Amish buggies.

That was actually a wonderful idea that Mr. Carter thought up of during the second gas crunch in the 70’s. Too bad, it never became very popular. Could you imagine if everyone drove 55 and under with basic hypermiling techniques? ...Less deaths, personal vehicle expenses, and of course less oil consumption.

Let us know how your FE does in future tanks, Rick!

BTW: Contentious driving? I'm more of a conscious driver. I’m passive when it comes down to driving...

Cheers!

[bkrownd]

Originally Posted by STC

I’ve gotten a few beeps (3 so far) and a couple of fingers... LOL!

What a bunch of selfish morons. Glad I don't live in road-rage country anymore! People are perfectly happy to go a sensible 45-50 here.

[STC]

Originally Posted by bkrownd

What a bunch of selfish morons. Glad I don't live in road-rage country anymore! People are perfectly happy to go a sensible 45-50 here.

Well, the drivers in my area are actually mellow drivers. It was on my trips to eastern PA and the big cities that I got those welcome responses...

[docB]

What kills on the highway is the difference in speed. Also, todays and the Carter era cars were designed to run best about 60-70 mph. 55 usually has a rhythme with the road that puts you to sleep. Todays stats show more people on the road driving a bit faster w/ less carnage.

I run 42 in the front tires, 35 rear. Less understeer. 15" Goodyears. The RE-92 is a mileage tire? With a tread rating of 160, that is not the case.

I also have a hard time with instantaneous FE figures. Track all the gas you burn and give me the milage from that. I have over 11k miles and am just shy of 40 mpg for allof them.
doc

[Freedan]

Wow, over 50 mpg!

I can't wait to fill up my tank for the first time to see my MPG.

If you are in Southern California and see a guy with a Bayou Blue Yaris dancing at the pumps in a week or so. It'll probably be me.

[STC]

Originally Posted by docB

I run 42 in the front tires, 35 rear. Less understeer. 15" Goodyears. The RE-92 is a mileage tire? With a tread rating of 160, that is not the case.

Actually, the Bridgestone Potenza RE92 165/65/14 and RE92 175/65/14 are LRR tires. The 185/60/15 is considered a LRR tire, but does not have a stamp to show. So, they are probably not? At least this is what I gather?

I also have a hard time with instantaneous FE figures. Track all the gas you burn and give me the milage from that. I have over 11k miles and am just shy of 40 mpg for allof them.
doc

Actually, these are not instantaneous figures. I track all my gas mileage from pump 'click' to pump 'click' and prior write down all the 'bar' drop 1/8 increments. On the tank when I fill up is usually on the 7th bar or the last bar (single flash). I add the total mileage once the pump 'clicks' and write down the amount of gallons on the pump. I always use the same pump. I have no Scanguage or Ecometer yet... so I can't use instantaneous figures. These are real life figures...

I had three consecutive 50+ MPG on the tank during the mid summer. I knew to make four in a row would be difficult since my driving would not involve taking any trips. I was correct. I was just short of 50... 49.349 MPG to be precise.

Cheers!

Gas Tank mile increments (non-ethanol gas used):
1st Bar drop (8/8) > 93 mi (93)
2nd Bar drop (7/8) > 78 mi (171)
3rd Bar drop (3/4) > 64 mi (235)
4th Bar drop (5/8) > 55 mi (290)
5th Bar drop (1/2) > 80 mi (370)
6th Bar drop (3/8) > 58 mi (428)
7th Bar drop (1/4) > 63 mi (491)
8th Bar drop (1/8) > 02 mi (493)

Tank total : 493 miles
Fuel used: 9.990 gallons
MPG: 49.349

[Yaris Hilton]

Originally Posted by bkrownd

However, the short recessed stem of the Yaris' wheel air valve has kept me from being able to increase my tire pressure above what the dealer put in. My home air pump can't get into that tight space. :/ Someday I will get a new pump...

It's a lot easier if you pull the wheel covers off. It's not hard to pull them off and put them back on, no tools required. Now I just leave mine off.

[docB]

I am glad STC is getting really awesome economy with the real numbers. I am pretty glad for the milage I get since my car has been near 100 mph a time or two. Mine is a cash for clunckers deal. Got rid of a 97 Crown Vic. No regrets. Also, this forum has been a great help. I killed my TPMS light via the postings so I can run my light weight Miata wheels. Better everything from the lighter wheels. Keep up the high milin'. The deal over a Prius really sweetens when a Yaris goes over 40 mpg.
doc

[STC]

Originally Posted by docB

I am glad STC is getting really awesome economy with the real numbers. I am pretty glad for the milage I get since my car has been near 100 mph a time or two. Mine is a cash for clunckers deal. Got rid of a 97 Crown Vic. No regrets. Also, this forum has been a great help. I killed my TPMS light via the postings so I can run my light weight Miata wheels. Better everything from the lighter wheels. Keep up the high milin'. The deal over a Prius really sweetens when a Yaris goes over 40 mpg.
doc

Thanks... Going from a Ford Crown Victoria to a Yaris is a major change. You must definitely see the difference in FE. What does a Crown get? 15 MPG? I see a major difference with my change from a Pontiac Sunfire. The Sunfire is said to be good in FE for the 2.2 engine. The Yaris blows the Sunfire away...

Unfortunately, I’m going to be doing a partial fill-up (at little over a half tank) by the 15th of this month. By that time the petroleum suppliers (Altoona, PA pipeline) of two of the last left Non-Ethanol stations in State College area will be converting to Ethanol gas. This is a reality from a law passing in both State Houses and signed by the governor several years ago. Already Philly and Pittsburgh areas/regions had to comply with EPA oxygenated gas standards (Ethanol use) because of their population. Now it is central PA’s turn. They (corporate/government crimeocracy) were pushing for it, and they got it! It just took several years later. The good thing is I can get my last complete fill in mid-October! The other gas station that carries non-ethanol gas will be filling their tank from the Altoona gas line in mid-October. Their tank is full and they expect to fill up then. They will make the necessary filter changes and pump conversion when they run out of the conventional gas.

This is progress for you? Now what are the farmers and small engine customers going to do here in Central PA? They will probably have to be fixing their engines and gas lines more often?

I have never been a fan of ethanol for two reasons:

1)The physical property (chemical chain) of ethanol... alcohol... Short shelf life, creates condensation in gas lines and fixtures, can rust older parts, doesn’t properly lubricate...

2)The inefficiency of how we produce the ethanol.

The higher gas mileage of non-ethanol is a benefit for me. Not much, though!. You only gain approximately 1-3 MPG more using non-ethanol conventional gas.

Cheers!