Thinking out loud, large cars

[zonker]

Originally Posted by instarx

It's little known, but in the late 90's the Volvo T5 5-cylinder wagon was the fastest production car in the world.

VERY little known. Was this the car that had the flag flying from the aerial? U know, the BS flag?

Maybe the fastest station wagon that seats 7 or some rediculous qualifier like that, but the fastest production car???

Seriously??!

In 1994 I bought a new LT-1 Corvette coupe, and that car would do 170 mph (I saw 158mph once myself).

And get 28mpg if i was to cruise it at 55mph.

I know that car was not even close to being the fastest production car for that given year.

[NHRABill]

Well Zonker I would never have believed they came with a 215 in a thousand years till I just looked it up at a few places and found that they did indeed come with 225/60/16 on a 1998 base model regardless if I am wrong with my size or you are wrong with your size

1998 Ford Crown Victoria 4 Door Sedan LX, Specs



it is still on a 3900lbs car that is crazy. on a 7" rim, to boot... wow not that is a Skinny tire for a good sized car... I was basing my experiences with my cars a 75 vette and a 87 firebird with 15 x 7 rims in the front and 15 x 8 in the back. Firebird is long gone but I still have the vette 20 years later and it now sports a 225/60/15 on the front Back tires fro both cars are 255 - 275

Given the decent power of the v8 crown vic I would have expected more i guess a lot of technology has changed in past 10 years on tires...

The cars in my driveway now are huge compared to that the Olds has 225 on the front the Wifes Cadillac has 245 or 255 one or the other in the front ad my truck well its a truck and that is different, wider rims..

Whatever the crown vic owner decides to use I am sure he will be more informed before he makes his choice than all of us in here.

[zonker]

I used a 1994 CV as my base for info, and the optional tire was the 225/60-16 with the 215/70-15 being the stock size.

tirerack.com is where i pulled the specs from.

On my '94 vette, I am running a smaller tire and wheel than stock.

oem for the '94 was 17x8.5 up front and 17x9.5 out back, with 255/45-17 and 285/40-17 out back. I went with 17x8's all around, with a 245/45-17 up front and 255/45-17 out back.

The vette people said I was crazy for doing so, but the car looks great and the handling/grip/tracking is all better than oem, thanks to increased wheel offset, modern tire technology and lighter wheel and tire weights.

[mystere485]

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.

why would he someone spend 3-400 or more dollars on new tires that make little to no difference? If the tires were still good, Id much rather experiment with a set of 4 $80 springs i bought at a local PYP.

and it wasnt the concept of active suspension, it was that manufacturers use active suspensions that "lower" the car at highway speed thereby decreasing drag. Lowering a car is on the list of mods here at ecomodder and is listed almost everywhere else as a drag decreaser with some limitations. So why would someone not try lowering it? other people have lowered their cars in this thread with semi-ok results.

Originally Posted by mcrews

Again, why lower it. REALLY. why? I can tell you from firsat hand experience there is no noticable difference in mpg w/ lowering.

Your basing your knowledge on the lowering issues on first hand experience. When you changed your springs, did you do any other modifications to your suspension when you swapped them out?

[instarx]

Originally Posted by zonker

VERY little known. Was this the car that had the flag flying from the aerial? U know, the BS flag?

Maybe the fastest station wagon that seats 7 or some rediculous qualifier like that, but the fastest production car???

Seriously??!

In 1994 I bought a new LT-1 Corvette coupe, and that car would do 170 mph (I saw 158mph once myself).

And get 28mpg if i was to cruise it at 55mph.

I know that car was not even close to being the fastest production car for that given year.

Oops, you're right. I misremembered. The T5R was not the fastest, but the quickest automatic transmission car (0-60), until 1997 when the Corvette bettered it. And probably few R's went to soccer moms.

[mystere485]

Originally Posted by instarx

Oops, you're right. I misremembered. The T5R was not the fastest, but the quickest automatic transmission car (0-60), until 1997 when the Corvette bettered it. And probably few R's went to soccer moms.

you were partly correct, the T5R was the fastest production station wagon when it was built.

[zonker]

Originally Posted by instarx

Oops, you're right. I misremembered. The T5R was not the fastest, but the quickest automatic transmission car (0-60), until 1997 when the Corvette bettered it. And probably few R's went to soccer moms.

Don't get me wrong, I do like the T5R's... they were badass volvos. Quick boxes with gunmetal rims...