Quote:
Originally Posted by mcrews
all I can say is .....doesnt ANYBODY read other threads!!!?????
hey run dounut spares for all I care.
you come on saying wowwwwoowowo me 40mpg!!!!
and then you tell me you going to go with a smaller tire???????
you have a BIG car. You just have to have a certain amount of tire on the ground to make the ride feel right.
if your so worried about 'frontal' run bike tires!
the point is, the gain from a taller tire in lower rpm is off set by a slight increase in hieght.
Beside, $20 of coroplast intantly lowers the car and reduces the 'frontal'.
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I proved your theory wrong in the other "thread", by switching from a 245 to a 255 you gained approx. 40,000 inches in one tank of gas. That is less than a mile gain per tank. Im not going to drive the car like i stole it, 195 would be fine and cheaper. I have a set of 195's on volvo rims that i can swap on the vic and do a test run, if they don't ride nice ill look into something else.
Dounut spares are not safe, I wouldn't suggest them to my lawyer.
At the beginning of the thread, I stated that I recently received the car. The car is not active yet. Right now it is a discussion on options for higher mpg. I am looking to get 40mpg out of the car when i am done, I have not gotten 40 mpg nor do i have a base line as of yet.
From the fore mentioned thread:
Quote:
Originally Posted by mcrews
Since 245 is the stock factory tire and 255 the tire I run.....oh and you can read any of my posts and see that I only refer to the advantage of ther one size up tire EVERY time as a key reason for my mpg.
AND I have used a Garmin 360 Nuvi to acuratly calculate my miles on long trips to ACCURATELY document the REAL miles and TRUE MPG
BUT here is the chart from TIRERACK.com on the Kumho's that I run.....
size 245/45ZR18 255/45/18
max psi 50 psi 51psi
tread depth 11/32" 10/32
weight 30lbs. 30lbs
rims 7.5-9" 8-9.5
overall width 9.6" 10.1
tread width 9" 9.3
diameter 26.7" 27”
rev per mile 778 769
-------------------------------------------------------
255/45R18
Section Width: 10.03 in 255 mm
Rim Diameter: 18 in 457.2 mm
Rim Width Range: 8 - 9.5 in
Overall Diameter: 27.03 in 686.56 mm
Sidewall Height: 4.51 in 114.55 mm
Radius: 13.51 in 343.15 mm
Circumference: 84.91 in 2156.7 mm
Revs per Mile: 769.5
Speedometer Difference: 1.312% too slow
Diameter Difference: 1.3%
same basic demensions would you say?
Heres the thing, I may not know everything about tires, but i do know math. You save 10 revolutions per mile, which is:
84.91 inches x 10 revolutions=849.1 inches per mile.
you have what? an 18 gallon tank, at your advertised average of 27mpg you are getting roughly 486 miles from one complete fill-up.
849.1 inches x 486 miles=41,2662.6 inches.
there are 63,360 inches in a mile, which means your getting less than one free mile per fill-up. if you can tell a difference its not from your tires, atleast not from a height stand point.