2005 Toyota Sienna with FP60 and LC20 mpg improvements

[biomed_eng_2000]

My 2005 Sienna has 30,000 miles on it. About 1 month ago I discovered FP60 and LC20. FP60 and LC20 are used at their recommended doseages. OCI is 5,000 miles using only Mobil 1 synthetic.

Without FP60 and LC20:
11 month average of 20.6 mpg

With FP60 and LC20:
1 month average of 21.6 mpg (current)

 

[jamesn]

hey, 5% is nothing to sneeze at. i got over 12% with a serious decarbonization and lots of FI cleaner on my 95 acura.

 

[moving2]

biomed- doesn't say too much when you are comparing 1 month and 11 month averages.

*Assuming* your mpg numbers hold for 11 months, and assuming a 20 gallon tank, 12k mi. / year driving, buying 1 gallon FP/LC, $3/gal. gas, it looks like you will save $80.91 in gas, and you will have paid $55.55 on the FP/LC, saving you $25.36 in a year.

The question is: will those mileage numbers hold for 11 months?

 

[biomed_eng_2000]

Yeah, I am pretty happy with the 5% improvement, after all, it's a pretty new car, only 12 months old.

 

[biomed_eng_2000]

I will answer in 10 months.
Care to wait? I may lose interest by then, haha.

But seriously, after running errands today, the 1 month average is now at 21.7 mpg.

I'd run FP60 if I didn't save any money just because it keeps the engine running smoothly and supposedly cleanly.

My wife is a sales rep and does all the driving in the Sienna. She asked what I did to the car because it runs more smoothly now.

 

[Titan]

My impression is by using FP I can then use non-name-brand fuel, and not worry about the quality of the additives that it has/doesn't have. I use it in every engine, including my lawnmower....it's a 7 year old B&S engine. Used to have to tinker with it sometimes to get it started. After several tankfuls, it now always starts on the first pull. Motorcycles run great on one level of Octane lower than usual...no pinging...even in hotter temps than before. Fuel mileage on my vehicles is significantly above the sticker estimates. Same story from my 77 year old father and his cronies. I have a hard time believing this stuff is not an actual benefit.

 

[TooSlick]

I'd wait until the weather gets cold again before making mileage comparisons. Fuel efficiency is always better in warm weather....

TS

 

[biomed_eng_2000]

I gather too hot (100+ F) is bad for mileage too. But maybe that is because most people run their AC at that temp.

Has anybody ever seen an ambient temperature vs mpg chart?

I am guessing 50F to 80F (Spring and Fall seasons) is the optimum ambient temp for best mpg.

I respect Scientific American, here is what they had to say about winter vs summer mpg: http://www.sciam.com/print_version.cfm?articleID=000BBB5F-0CF9-1080-8CF983414B7F0000

 

[Titan]

I generally like Scientific American, too. But, they have two non-sense points in that article. One is, slipping on ice hurts fuel econmomy. Bunk. The odometer turns due to the transmission rate of speed, decrease the resistance to the point of slipping and the transmission speed increases, so does the rate of odometer turnover....yielding a false better fuel economy. Another bunk is Aggressive drivers get worse economy than cautious drivers....depends on the definition of aggressive and cautious. On a manual transmission car, I will coast down Interstate 40 (and several other highways) at 85-90 mph...I'd call that aggressive driving...however I'm getting better mpg than the cautious driver keeping the car in gear and even putting on the brakes to keep the speed down. Also, in town, if my speed is up high enough to just barely make it around a downhill turn...guess what...I'm in neutral and coasting around corners with the tires squealing. Aggressive, but, getting better fuel economy. In REAL LIFE driving, I get very close to Hwy estimated MPG when driving in the city...and everyone that rides with me will tell you I'm aggressive in driving...not impolite to others on the road, but, I do allow the limits of the cars' handling to be approached often. On the Hwy, I always exceed the estimated MPG, sometimes by as much as 25%. I coast down hills steep enough to allow me to maintain speed. I'm just saying, for a Scientific rag, they make some very unscientific comments.

Alas, now, I have two automatic vehicles....well, there goes my great fuel economy...

 

[surfstar]

Off topic:
Titan if you search, you will find at least two discussions on coasting vs leaving the car in gear (manual) and keeping the throttle closed. FI cars should get better gas mileage with it in gear, as no gas is used to keep the engine idling as it is when in neutral.

 

[Titan]

surfstar...bulloney. Throttle closed and coasting with the car in gear SLOWS the vehicle down....that cost of slowing shows up as you must then use fuel to regain the speed that was free due to gravity. Well, almost free...the engine does have to idle, which uses a minute amount of fuel per unit time.

If you aren't trying to slow the vehicle, the tiny bit of fuel used to keep it idling while you coast at a decent speed downhill, and the resultant momentum you can then use to help you get up the next hill, will far outweigh having to use the fuel required to re-gain the speed you lost while coasting in gear. Coasting in an automatic doesn't "cost" as much speed as coasting in a manual. That's good, because I don't think it's a good strategy to pop an automatic transmission into neutral and back into gear...it's not as benign as doing that with a manual transmission.

Do the following thought experiment: Imagine you've just crested the top of a steep, long hill at 60 mph. You let off the gas pedal and coast in gear to the bottom. Let's say the hill is steep enough that you don't lose speed, in spite of the drag of an engine being FORCED to keep rotating by the mass of the car as gravity pulls it downward. That FORCE is energy. You are wasting the energy producing the FORCE that is dragging on the transmission with an engine that is trying to stop, since there is no fuel being delivered.

Now, put that same car in neutral as you crest the top of the hill...that same car will now accelerate due to gravity, so, you may be going 70 mph, or even faster at the bottom. There are hills I go on on I-40 where I can be coasting at 90 mph. The COST is only the amount of fuel it takes to idle during that time. If you had to accelerate from 60-70 or more mph on a flat road, how much FUEL would that cost? I guarantee you the amount of EXTRA fuel required to increase your speed 10 mph at those speeds will far exceed the amount of fuel burned by an idling engine. FURTHERMORE: NOW, when I reach the bottom of the hill...the coaster is going 10 mph faster! The coaster now has the option to capture some of this momentum and help to decrease the fuel energy cost of going up the next hill.

Synopsis: There is a lot of fuel energy cost incurred to accelerate a car from 60-70 mph. Or, there is only the tiny fuel cost to do so if you idle in neutral and let gravity provide the energy.