Tire Size vs Economy

[astroturf]

Alright guys here it is.
My vehicle stock size tire is 215 70 16 (#1).
That size being one choice, I have two others that I'm willing to make.
They are 255 60 16 (#2), and 215 85 16 (#3).

Stock size tire #1 is 27.9 in diameter and weighs 28 lbs.

Tire #2 is 28 in diameter and weighs 32 lbs.

Tire #3 is 30.4 in diameter and weighs 38 lbs.

All tire sizes noted above will support the vehicle weight, and #1 & #2 have a max psi rating of 51. #3 has a max psi rating of 80.
Speed rating on all tires is S.

Now here is the question:
Which is best for economy and why?
Please give an explanation other than so & so says, or so & so has a link in his signature.
Thanks, Jim

[theholycow]

Is your driving more stop-and-go or more highway? If the differing weight of the tires will make a large difference, it will be in stop-and-go driving. Also in stop-and-go driving, the gearing advantage of taller tires won't help as much and may even make things worse (since your Astro probably has some decent gears already).

[GasSavers_Bobert]

I wouldn't go with either choice #1 or #2 but go with 215/75R16. Slightly taller, and doesn't have the extreme weight penalty.

Not sure if your looking for a truck tire, but the Latitude Tour has the GreenX technology in that particular size which has LRR. Also Michelin has $70 Rebate now.

http://www.tirerack.com/tires/tires....omCompare1=yes

[astroturf]

Originally Posted by Bobert

I wouldn't go with either choice #1 or #2 but go with 215/75R16. Slightly taller, and doesn't have the extreme weight penalty.

Not sure if your looking for a truck tire, but the Latitude Tour has the GreenX technology in that particular size which has LRR. Also Michelin has $70 Rebate now.

http://www.tirerack.com/tires/tires....omCompare1=yes

1 lb heavier, now here is the question. Why?

[astroturf]

Originally Posted by theholycow

Is your driving more stop-and-go or more highway? If the differing weight of the tires will make a large difference, it will be in stop-and-go driving. Also in stop-and-go driving, the gearing advantage of taller tires won't help as much and may even make things worse (since your Astro probably has some decent gears already).

running a 3.42 gear, 60% city, 40% highway. Current avg mpg 18.4

[GasSavers_Bobert]

Originally Posted by astroturf

1 lb heavier, now here is the question. Why?

Well your choice #1 is too extreme in width. Pretty sure your gas mileage would go down in city and highway. Choice #2 is too heavy, and could kill your city mileage, however if you did a lot of highway miles (like 90%) it might be ok. The problem is people go to extreme one way or the other. I'd make a small change and go slightly taller -- shouldn't kill your city mileage with only 1 lb change and improve highway mileage lowering your engine rpm slightly. The Latitude is also LRR so that is an added benefit.

[astroturf]

How about my current tire 215 70 16 Nokian WR G2 SUV?

[GasSavers_Bobert]

I'm really not familiar with that tire, so couldn't really comment on it. That particular tread design looks to be a better snow tire if you need that capability.

[GasSavers_Scott]

On my Explorer I used to have, I went with the stock size on the door, funny none of the tire stores carried it, so I had to order the size. It was made by General tire and it was cheap, I got 2 for 120 bucks back in 06, the tire store guy said he didn't keep them in stock, because they were so cheap, but since I asked for that particular size, he ordered them for me. The next month I got 2 more, great little disposable tires, my father loves to put huge tires on his SUV's. I went from 16 mpg to 20 average by getting the right size.

Now my father has a new Jeep 3.7 SUV, he averages 12, I drove it for a week and got 24. He drives foot to the floor in the city and goes from 75 to 50 to 75 on the highway. I have watched him drive like this, oscillating for the last 40 years. LOL, he might be behind you right now.

[theholycow]

I'd guess that Bobert's LRR tire suggestion is your best bet, unless some hard data can be found.

Scott, it sounds like your dad is almost pulse & gliding, just get him using neutral as he goes from 75 down to 50 and he should gain some fuel economy...