I put on 275/65/20 on my truck. I know I can't count on the computer to
tell me an accurate reading of mileage per gallon. Currently getting
a reading of somewhere around 12 mpg highway. Anyone know anyway of finding out? Sorry if this post is in the wrong place.

 

Dividing the OD of the stock tire and the OD of the new tire will give you your percentage factor difference. Multiply that by any given mile per hour to get your real MPH, Multiply by what your MPG used to be to get what you re getting now.

 

IMO the most accurate method of mpg is to start your tripometer back to 0 when you fill up then divide it by your gallons on your next fill up.

 

^^^Agreed. That's how I do it everytime.

 

Which is still inaccurate if he has not had his computer reprogrammed for the new size tires.

Without programming, go to the tire calculator at www.discounttire.com. It will give you the difference in your speedometer so you can come close to calculating the real mileage you put on.

 

you'll never get a real accurate reading but I have this formula LOL I been keeping track of the mileage on one of my work trucks with oversized tires on it:

you have to find somewhere to get the diameter differences between your stock size and the new tire size.
Y is the differnce between stock spped and new speed. 10mph stock but 10.7 new speed
Z is the same but at say 70mph stock and 75.1 new speed

trip / 10mph = A, A x Y = B , B + trip = C

trip / 70mph = D, D x Z = E, E + trip = F

F - C = G, G / 2 = H, H + C = I, I divided by gallons = J (J = mileage)

it should look similar to this:

95 F150 with 31x10.50x15 tires does 10.7 mph at 10mph & 75.1 at 70 mph

so if the trip is 268 miles:

268 / 10 = 26.8 26.8 x .7 = 18.76, 268 + 18.76 = 286.76
268 / 70 = 3.828 26.8 x 3.828 = 19.526, 268 + 19.526 = 287.526
287.526 - 286.76 = 0.766, 0.766 / 2 = .383, 286.76 + .383 = 287.143

used 15 gallons so.. 287.143 / 15 = 19.142 miles per gallon

hope you can make sense of that LOL

 

Since you mention the economy, thought you might like to read the following:

A little over two year's ago:

1) Consumer confidence stood at a 2 1/2 year high;

2) Regular gasoline sold for $2.29 a gallon;

3) The unemployment rate was 4.5%.



Since voting in a Democratic Congress in 2006:

1) Consumer confidence plummet;

2) The cost of regular gasoline soar to over $3.75 a gallon;

3) Unemployment is up to 5% (a 10% increase);

4) American households have seen $2.3 trillion in equity value evaporate

stock and mutual fund losses);

5) Americans have seen their home equity drop by $1.2 trillion dollars;

6) 1% of American homes are in foreclosure.


America voted for change in 2006, and we got it!

Remember it's Congress that makes law not the President. He has to work with what's handed to him.

 

while political discussion has its place, let's keep that to the general discussion boards. the idiots over there need something to stimulate their brains anyway.

 

1. the government does not control gas prices, unless you happen to liver in a communist country.
2. Economic theory says optimal unemployment is 4-6 %. too little and inflation rates spike. with low unemployment you have a lot of idiot people making things, but badly.
3.that was in the making before the new congress, and the government has minimal control in that area.

im not a democrat, but most problems in politics should not bwe blamed on one person or group, because of the vast number of people that are responsible for making even one law.

 

I would have to agree. It also makes it easier for the rest of us to avoid ALL the idiots.