A search for tires...?

[sarguy01]

So, I am reading up in various threads on here and across the internet. I don't really have a question, but some thoughts...?

I have a 2006 Pacifica with 3.5L. My wife stole my new Sentra. I am averaging about 24-25 mpg straight and level at 60 mph. I drive mixed highway and city. Accelerating in this thing KILLS mileage. According to SGII, it is 6-10 mpg until I stop accelerating. I go by TPS position to keep my accelerating in check. At idle it reads 12 and I keep it under 25 unless traffic is heavy, in which case I will not let it go above 30. Full pedal is somewhere around 78?

Anyway, getting closer to the reason I started this thread. I have 63,500 miles and the original tires. They are 235/65/R17 Michelin Energy MXV4 Plus's. They are LRR's (low rolling resistance), but the max sidewall pressure is only 44 psi, which I am currently at. They weighed 32 pounds a piece when new. They are 880$ a set.

I need new one's soon. I could make these last another 5000ish miles or longer, but winter is fast approaching and I need this vehicle to get me to work.

So, reason for thread. I could get new LRR (Low rolling resistance) tires. There are several choices. ContiProContact's are 44 psi max with a weight of 27 pounds for 436$. GoodyearAssurance Fuel Max's are 51 psi, 27 lbs, and 452$. Grabber HTS's are highly rated at Tirerack.com and 51 psi, 33 lbs and 480$. Shipping is another 45$.

I could get a set of non-LRR's that cost 400-800$+ and weigh between 27 and 33 lbs with pressures of either 44 psi or 51 psi.

Or, I could just get a decent used set of 4, in whatever various brand, in my size for 100-200$.

I am also thinking about different tire sizes. Maybe a narrower but taller tire for the highway mileage? Or for acceleration, a narrower and shorter tire?

Without any testing, all I have are ideas. Tires aren't exactly something I can just try out and return if I don't like them. I could get worse mileage with a new tire and really be, for a lack of a better word, sucking.

Whats best? A lighter tire with higher sidewall pressure?

So, does anybody have anything to add? Criticize, insult, confuse at will. I am looking for the best mileage for the least amount of money.

[euromodder]

Originally Posted by sarguy01

They are 235/65/R17 Michelin Energy MXV4 Plus's. They are LRR's (low rolling resistance), but the max sidewall pressure is only 44 psi, which I am currently at. They are 880$ a set.

I could get new LRR (Low rolling resistance) tires. There are several choices. ContiProContact's are 44 psi max with a weight of 27 pounds for 436$. GoodyearAssurance Fuel Max's are 51 psi, 27 lbs, and 452$. Grabber HTS's are highly rated at Tirerack.com and 51 psi, 33 lbs and 480$. Shipping is another 45$.

At these prices it looks like a no-brainer ... if you can get at least say 40.000 miles out of these.

I am also thinking about different tire sizes. Maybe a narrower but taller tire for the highway mileage?

A narrower tyre will need to have a higher profile to match the overall diameter.

Or for acceleration, a narrower and shorter tire?

A smaller diameter will increase rpm at any given speed over what you're doing now - more rpm normally translates in more fuel used.

What's the rim width of your wheels?
What's the narrowest tyre you can legally fit ?

A lighter tire with higher sidewall pressure?

I'm having a tough time seeing any FE improvements from my new more aerodynamic wheels, which are some 6 lbs heavier than the wheels they replaced.
These 6 lbs can be felt in the heavier steering, and are likely fighting every acceleration !

I'd go for a lighter tyre with higher sidewall pressure.
If you can go narrower while keeping the original overall diameter, that'll normally also reduce weight.

[busypaws]

1) I'd buy new. I go for used when a single tire goes out and I want something to -- get buy for 1/2 year untill I replace them all.
2) I'd put sidewall pressure at the bottom of the list. Difference between 44 and 51 probably not as important as Size and LRR.
3) At your normal highway cruze speed do you "feel" that the RPM's are too high. If so then investigate larger diameter. If not then the larger diameter lowering the RPM's but increasing aero resistance will probably be a wash.
4) Check your rim width and see if you can go with a 215 or 225 wide tire. If you can then do they make LRR in 215/70 or 225/70 that might work.
5) Go to some of the tire company sites to get the ratio of old/new size. So you'll know when your spedo says 55 you are really doing 57 or something similiar.
Just the method I would use if I were in your shoes. Only speaking from experience not any special knowledge.

[autoteach]

your % load has more things in it than just the TPS. That has a very direct effect, but RPMs make a significant difference. I am guessing that is what you mean by all the numbers with no values or corresponding assigned descriptor. If you want to have a lower load, OR HIGHER, you need to change more than just your TP or RPM's as the torque curve of the engine plays a major role in the %load you will need to use at different speeds.

[sarguy01]

Originally Posted by euromodder

I'd go for a lighter tyre with higher sidewall pressure.
If you can go narrower while keeping the original overall diameter, that'll normally also reduce weight.

There are tires that are lighter and higher sidewall pressured in LRR available.

Narrower LRR tires that have a higher sidewall pressure and are lighter are also available. The only problem is the diameter decreases slightly. There are no tires that are skinny as tall as I need them to be.

4) Check your rim width and see if you can go with a 215 or 225 wide tire. If you can then do they make LRR in 215/70 or 225/70 that might work.

Tirerack.com does not show a LRR in either of those sizes. I am going to look in other places.

your % load has more things in it than just the TPS. That has a very direct effect, but RPMs make a significant difference. I am guessing that is what you mean by all the numbers with no values or corresponding assigned descriptor. If you want to have a lower load, OR HIGHER, you need to change more than just your TP or RPM's as the torque curve of the engine plays a major role in the %load you will need to use at different speeds.

I am still perfecting my driving. I am going to switch over to % Load and see if it helps.

I am going to actively pursue new tires after this weekend.

[sarguy01]

More bad news. Since new tires have more tread, I am most likely going to lose mileage because of the switch to new tires. I just read that on Tirerack.com. Some people were complaining they lost mileage after switching to an LRR.

Unless of course the tires I am going to get have much less rolling resistance than the worn ones I have now.

[euromodder]

1010Tires have a useful tire size comparison tool :
Tire Size Calculator - tire & wheel plus sizing


I've had a look, but your original tire size is a fairly odd one with a high profile for the width of the tyre - at least by European taste.

It means that a narrower tyre would need to have a very high profile (70, 75 even).
I'm not sure wether these are regularly available.

[sarguy01]

Originally Posted by euromodder

1010Tires have a useful tire size comparison tool :
Tire Size Calculator - tire & wheel plus sizing


I've had a look, but your original tire size is a fairly odd one with a high profile for the width of the tyre - at least by European taste.

It means that a narrower tyre would need to have a very high profile (70, 75 even).
I'm not sure wether these are regularly available.

You are correct. The 65 sidewall is pretty tall. There are no LRR 225/70 or 75 tires. The 225/65 is 28.6 inches in diameter and the 235/65 is 29.1 inches in diameter. So, there is a .5 inch difference in diameter.

I am wondering if a thinner, lighter (27 vs current 32), higher pressured tire's increase in mileage will overcome the mileage loss because of slightly higher revs per mile.

[orange4boy]

Look into Nokian. They make an excellent range of LRR tires which are also non toxic. I'm sold on their tires. I have the wrg2 on my prius and they are fantastic.

Nokian eNTYRE

[320touring]

Thinking about this from a "Resource use" point of view...

Would it not be more suitable to get a set of part worn tyres for circa $100-200 and get 20,000 miles, then do it again?

That way your costs are 1/2 that of new tyres, and you get the same mileage from the tyres. Cost of slightly lowe MPG if they are not LRR would be offset by savings

They're "Scrubbed in" so no major drop off in FE once the "new" tyres are fitted

You've reused 2 sets of tyre, rather than buying a new set-with the additional oil etc involved

Just thinking about this from a different perspective!

If you think about it, folk are happy with buying 2nd hand cars that sit on "used tyres" and dont give it a second thought..