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-   -   Potential fuel economy gains between 44 and 51 PSI? New tires choices. (https://www.fuelly.com/forums/f8/potential-fuel-economy-gains-between-44-and-51-psi-new-tires-choices-13840.html)

add|ct 09-15-2011 08:27 PM

Potential fuel economy gains between 44 and 51 PSI? New tires choices.
 
Well, it's about that time to replace the tires on the VX. The plan was getting a set of 4, by winter, and then I see an offer in my Costco coupon book for the next few weeks on Michelin tires. $70 off, instant rebate.

I am torn, in part because of price(yeah, times are tough you know the story lol).

I can get 4 Michelin X-Radial(the Harmony/Destiny model) installed for $290 or so with lifetime balancing, etc etc. 80,000 mile 'warranty', so the 'increased' treadwear rating is of some value, especially dealing through Costco. Max PSI sidewall rating is 44, the size is 175/70/R13.

I really would like to get the Sumitomo HTR T4's since their max sidewall PSI rating is 51 PSI, and I would feel comfortable riding them at around 50(unless strange suspension related issues were to arise, roads aren't bad around here so IDK...)...but I see better overall ratings for the Michelin, and I can save at least $50 up front($65 if I go through a tire shop directly without purchasing myself/paying someone else to install).

Would the 'potential' economy gains from 44 - 51 basically be towards replacement tires assuming the Sumitomo tires wear out faster than the Michelin? How long before I got the extra $50-$65 back? Currently getting around 40 MPG in the VX(long story, as most site readers know I have a clutch that is affecting FE currently).

Sumitomo offers the OE tire size for the stock wheels I have(165/70/R13), and currently the vehicle has the next best thing installed(175/70/R13), which is what the Michelin tire would be. Current tires have a Max PSI of 36; lame Primewell tires, so I figure I'll be seeing some increased FE with either tire after 'break-in' period.

Just having a tough time deciding is all.:D

Yes, I want fuel savings, but not at the cost of a 'lesser' tire or one that doesn't wear as well, etc. I can't get enough opinions about the HTR T4 overall and the Michelin is rated very well by reviews. Ugh!:confused:

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

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

theholycow 09-16-2011 05:03 AM

Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.
 
If it were my car and money, I'd take the Michelins without much indecision at all.

Here's my logic:

1. There is just not sufficient data to compare rolling resistance, so it's always a crapshoot.

2. 44 vs. 51 psi rating isn't much of a difference, and if you really want to run 50 you can run it on the 44-rated tires just fine. With such a lightweight car I don't think it will help.

3. Treadwear warranties generally aren't worth much, but, along with UTQG ratings (which are not at all 'U' but still seem to be vaguely worthwhile anyway) you can get a pretty good idea which tire will last longer.

4. Michelins are known for their long treadwear, and for premium quality in general.

5. Long treadwear that you can be confident in, along with actual cash, are sure things...the potential for better FE is not. Known variables are more important than those that you can only guess.

6. Lots of good reviews = good thing.

The only doubts I'd have are the size issue and the thought that, IIRC, lots of VX owners do well with the Sumitomos.

add|ct 09-16-2011 06:24 AM

Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.
 
Thanks for your response HC.

I think I'll have to choose the Michelin's this time, especially considering the Sumitomo's are the ONLY size I can find that matches originally equipped.

If/when these new Michelin's wear out, and the Sumitomo's are still around(assuming I have the car, etc), I'll try them out at that time. Of course unless I'm blown away at the Michelin's I'm about to put on.

Any money saved right now can help and my long-term goal is needing to replace the clutch/Input Shaft Bearing on the transmission, anyway.

I'll try the new tires at 44 PSI for a while to see how things go with handling/steering and the suspension.

trollbait 09-16-2011 07:48 AM

Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.
 
Quote:

44 vs. 51 psi rating isn't much of a difference
It is half a bar difference, which is what the psi ratings are converted from, 3.5 and 4 bar for 44 and 51 psi.

add|ct 09-16-2011 07:55 AM

Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.
 
^Half a bar? <Newb.

theholycow 09-16-2011 08:26 AM

Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.
 
Bar is another measurement scale for pressure. I'm not a fan of it because its units are too large, requiring decimals for detail...hence 3.5 bar being approximately 44psi.

benfrogg 09-16-2011 09:38 AM

Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.
 
Well, you already know my stance on the Sumitomos.
A quick summary-
Better winter performance than "cheap tires" (old continentals and pirelli p3000's rear). Better wet performance too. Way better rolling resistance than the pirelli's. Stock size is a huge bonus, no more correcting for off speedo.
Higher pressure rating is nice. I run mine at 65 psi anyway with no issues other than a stiffer ride.
Thy were the cheapest option for me at the time.
Price is a big factor though....
To concur with HC, there's an old saying.... the devil I do know is better than the devil I don't know.... So if the reviews are good, go for it.
B

add|ct 09-16-2011 03:52 PM

Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.
 
So, I went for the Michelin X-Radials today. :D

They're performing great so far! Road noise is so much better, wow.

Handling feels like stock again, as in when recently I first replaced the tie-rods back mid-June. Coincidence?

One of the wheels needed an extra weight at that time, I think it was the Primewell tires being of poor quality and allowing for a 'hop' at certain speeds.

Today, the wheels were randomly put back on the vehicle since all 4 had brand-new tires, so I'm not sure but IMO the Primewell tires; when moved to the front after the tie-rod work was performed, made handling terrible again.

I had thought that perhaps a bad wheel was suddenly thrust back on the front of the vehicle again, so there was some concern I may need a replacement wheel. So far, not the case.

The improved steering alone will help with throttle control in a lot of different scenarios, instead of having to focus too much on steering I can focus on the angle I take turns, throttle position/gear selection, etc.

So, overall very impressed so far with the tires for the deal they were installed at $293 with life-time rotation, balancing, 'nitrogen' air fills, etc.

The only other concern is this: Costco's information given to me, states the pro-rated warranty doesn't apply if I run the PSI at other than stock settings? Yet, their paper has them at 32/32, whereas stock is 35/32.:confused:

I doubt I'll need to argue such a warranty, but you never know? Always 'restore' proper inflation when going in for the free rotations??

trollbait 09-16-2011 07:40 PM

Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.
 
I was just looking at tires for the HHR, and Costco seems to be the best value. Selection sucks, there wasn't a Michelin available for my car, but the BF Goodrich Traction T/As for my sole choice are a good tire.

With all the add on charges the others add on, cheap tires ended up costing as much as the BFs. I could save some by dropping the road hazard, but it's included with Costco's mounting fee.

theholycow 09-17-2011 03:11 AM

Re: Potential fuel economy gains between 44 and 51 PSI? New tires choices.
 
Mark the wheels before each time anyone removes them, that way you can keep track of which wheels move where and correlate that with any noticeable changes in handling.

It might be worth going back to stock inflation when you go in for rotations. However, I suspect that, if they show visible center wear at the end of their life, that will be used as evidence that you ran overinflated. I'd suggest getting the paperwork corrected but I imagine they will outlast the warranty...in my experience, overinflation usually helps total tread longevity even when it shows some center wear.


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