*The official what works to improve miles per gallon thread*

[Compaq888]

Can we make this a sticky??
It might help the new people out more.

Here is all the things that work and it will be in the 1st post. It will be updated if members have any more ideas.

-Overinflating tires

-Getting a credit card with cash back on gas purchases.

-Airdonamic mods

-Engine block heater(allows the motor to go into closed loops faster to save fuel)

-Pulse and glide technique

-Low Rolling Resistance tires

-Less weight in the car (especially rotating weight).

-Hotter Thermostat

[Matt Timion]

Originally Posted by Compaq888

Can we make this a sticky??
It might help the new people out more.

Here is all the things that work and it will be in the 1st post. It will be updated if members have any more ideas.

-Overinflating tires

Jury is still out on this one. A few months ago flatland2d overinflated his tires and no zero net benefit.

Originally Posted by Compaq888

-Getting a credit card with cash back on gas purchases.

This is a great way to save money, but obtaining a credit card will not make your car get better gas mileage.

Originally Posted by Compaq888

-Airdonamic mods

aerodynamic mods will help with gas mileage on highway trips.

Originally Posted by Compaq888

-Engine block heater(allows the motor to go into closed loops faster to save fuel)

For this reason I'm assuming it works, but we're still waiting on data to back this up.

Originally Posted by Compaq888

-Pulse and glide technique

Works really well on the Prius, but might not work too well on other cars. Flatland2d tried doing pulse and glide a while ago and once again found no benefit. I'm thinking this technique is wonderful for some cars and not others.

[krousdb]

Originally Posted by Compaq888

-Overinflating tires

Jury is still out on this one. A few months ago flatland2d overinflated his tires and no zero net benefit.

I have actually done a lot of testing with overinflated tires. The following is a report from last summer. I had just switched to a new set of OEM tires which ended up dropping my mileage by 6%:

July 2005:
Well I'm back and the results seem to make sense, although I am a bit
surprised.

My first test was with the new tires (approx 5000 miles on them) at
62/62 PSI. The MPG was as high as 99.9 (100+) and as low as 96.3.
The final MPG was 98.8 at 77F. The low of 96 seems to confirm my
previous 104+ reading because at no time did it drop below 99.9 on
the 104+ MPG test.

For the second test, I dropped the pressure to 44/42. For the trip,
97.4 MPG at 82F.

For the third test, I dropped the pressure to 35/33. For the trip,
96.0 MPG at 86F.

I did expect the 6 MPG drop by switching to the new tires (my guess
was 3-5). I guess they have more breaking in to do. The larger
circumference of the new tires (due to full tread depth) had no
effect on the trip length as indicated by the trip odometer, which
was 23.4 miles. Actual measurements of the tires showed 77 3/16" for
the new and 76 3/4" for the old. The difference is about 6 tenths of
one percent, negligable in my opinion.

I was surprised however that tire pressure made such a small
difference, although the MPG's may be skewed higher due to the higher
ambient temps during each sucessive test. I guess what this tells me
is that if you spend most of your drive below 42MPH, you might see a
benefit in raising your tire pressure. Otherwise, you will not
likely notice a difference. The other thing it tells me was that
yesterday's results were not a fluke. These MPG's are repeatable.

My old set of tires spend most of thier lives at 50PSI. The wear on
them is perfectly symmetrical. Anyone who tells you that high
pressure will cause uneven wear, IMHO, is misinformed. The even wear
is also a testament to a prefect wheel alignment. If your tires are
wearing unevenly, have your alignment checked.

Based on these results, I will keep the new set on and drop the
pressure to 44/42. My ride to work is partially on a very bumpy
stretch of I-79 (Andy can attest to this) and the 44/42 PSI yields a
noticably better ride. The 35/33 yields an even better ride, but I'm
not quite ready to give up all of my advantages. The new tires will
probably drop my summer mileage from the low 70's to the mid to upper
60's. I guess thats the price I will pay for new, safe tires.

[krousdb]

Originally Posted by Compaq888

-Engine block heater(allows the motor to go into closed loops faster to save fuel)

For this reason I'm assuming it works, but we're still waiting on data to back this up.

I agree it should save fuel. Faster closed loop is a good thing but I believe the most of the savings will come from the elimination of the ECT compensation. Under heavy loads and very cold temps, the multiplier is 1.75. Even at 52F and light loads, the multiplier is 1.14, and at 128F, 1.09. An engine block heater should nearly eliminate compensation completely. At least that is what I see when looking at the tables that SVOboy posted. I hope to have an engine block cleaner installed this weekend, test results coming next week sometime.

[diamondlarry]

Compaq888 wrote:
-Pulse and glide technique
Works really well on the Prius, but might not work too well on other cars. Flatland2d tried doing pulse and glide a while ago and once again found no benefit. I'm thinking this technique is wonderful for some cars and not others.

One of the cars that this works very well on is Fran Giroux's Saturn. He was able to achieve just over 109 mpg over a 150+ mile trip in last year's Tour de Sol. Of course, once they got done screwing him over, his official mileage was 99 mpg. I would say that pulse and glide-or porpoising as Fran calls it-works and works quite well.

[krousdb]

Originally Posted by diamondlarry

One of the cars that this works very well on is Fran Giroux's Saturn. He was able to achieve just over 109 mpg over a 150+ mile trip in last year's Tour de Sol. Of course, once they got done screwing him over, his official mileage was 99 mpg. I would say that pulse and glide-or porpoising as Fran calls it-works and works quite well.

IIRC, that was the car with hydrogen injection. They accused him of porpoising. I was surprised to hear that because I didn't think there was anything in the rules about that.

[kickflipjr]

Here is what I will add:

-Low Rolling Resistance tires

-Less weight in the car (especially rotating weight).

[diamondlarry]

IIRC, that was the car with hydrogen injection. They accused him of porpoising. I was surprised to hear that because I didn't think there was anything in the rules about that.

There wasn't anything in the rules about that. Fran was very careful in following the rules exactly. He wanted the results to be as accurate as possible so he would have proof that his system worked. If you look at the list of sponsors for last years TdS, it becomes quite clear that it would have been a major embarrasment to those sponsors if a worn out 1996 Saturn with less than $1000 worth of retail priced equipment would have been allowed to win. I also think that it was a major factor in thier decision to exclude these types of cars in the 2006 TdS. I have officially been told that there are no categories for me to compete in. Fran is banned for life because he accused them of rigging the rally so the sponsors would look good. Okay, I'll calm down and get off my soapbox now.:-)

[Matt Timion]

Originally Posted by diamondlarry

There wasn't anything in the rules about that. Fran was very careful in following the rules exactly. He wanted the results to be as accurate as possible so he would have proof that his system worked. If you look at the list of sponsors for last years TdS, it becomes quite clear that it would have been a major embarrasment to those sponsors if a worn out 1996 Saturn with less than $1000 worth of retail priced equipment would have been allowed to win. I also think that it was a major factor in thier decision to exclude these types of cars in the 2006 TdS. I have officially been told that there are no categories for me to compete in. Fran is banned for life because he accused them of rigging the rally so the sponsors would look good. Okay, I'll calm down and get off my soapbox now.:-)

Looks to me like there needs to be an alternative to the TdS... perhaps on the west coast?

[Compaq888]

wow you guys really chopped up my stuff. Yes it does matter what tires you use for overinflating. Some tires just don't work with this strategy.