Michelin Energy Saver - psi?

I'm running at 50-55 PSI at present. And I've done so since 2009 when they were put on. I'll be replacing them in about 10k miles, which puts the fronts at 75k miles. I'd consider going higher, but the spouse just cannot keep the speeds down enough that I'd consider it safe.

 

I have been keeping my Michelins at 44 psi, and that is definitely a worthwhile improvement over the 32 psi that the dealers seem to favor. Do you find that 50+ psi is much better? On bumpy roads, I think the ride and wear on the suspension is harsh already. Where is the point of diminishing returns?

 

Do you have the Energy Saver (summer tire) or Energy Saver A/S (all-season tire). Pretty big difference between the two. The A/S is the mpg king. I would make certain you have the A/S. if not then I would return them and get the correct ones. You wouldn't bethe first who were accidiently sold the wrong tires.

Most 195/65/15 tires are rated 44psi max. Even the S rated Fuel Max tires are rated at 44psi. It's the H rated version that is 50psi.

I have been running 40/38psi the 44/42psi and I do not notice a big difference in fuel economy but I do notice a big increase in ride harshness the higher I go. For the tests and papers I have read the fuel economy savings starts to diminish quickly after 40psi and pretty much maxes out at between 45-50psi.

My recommendations:
1. Mostly urban driving at low speeds and decent roads = max out the pressure to whatever you are comfortable with
2. Mostly urban driving at low speeds with crappy roads = drop pressure to no more than 44psi
3. Mostly highway driving at higher speeds with good roads = 44psi or lower
4. Mostly highway driving at higher speeds with crappy roads = 38psi or lower but no lower than 35psi.

 

The original Energy Saver summer tire is older. The A/S is newer and thus uses newer technology. It also has a longer tread life.

The reason for lower pressure on bad roads is to reduce tire skipping. A very hard tire willbe more likely to deflect off road irregularities instead of conforming around them with minimal reduction in speed. Burst pressure is important but it's so high I am not concerned with it since I never run higher than 50psi.

Here is a bit more info on LRR tires.


Tire Review - Rolling Resistance: What Really Makes a Tire Fuel-Efficient?

 

Obviously narrow racing bicycle tires are a different kettle of fish, supporting the weight of the bike and rider on a very narrow contact patch.

I also think there are diminishing returns from increasing pressures too much. I find about 42/40 or 44/42 to be a pretty good choice.

 

There are good threads on the subject of rolling resistance and tire pressure.

Experiment: coast down distances (rolling resistance) @ various tire pressures - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

While the tests are not perfect, it appears to confirm many other tests and anecdotes that claim the point of diminishing returns for most small passenger car tires is between 45psi and 50psi.

 

Oops, here is a better link

Snapshot: effect of tire pressure on rolling resistance - MetroMPG.com

 

I did a search and couldn't find the coastdown test link on this site. Here is one from GrassRoots Motorsports. It is also an Excel spreadsheet.

 

im in the UK and looking at getting the energy saver Michelin tyres but blackcircles.com doesnt list whether they are the all-season varierty or the summer tyres.

very annoying.

I was also looking at the crossclimate+ although I live and drive in london which rarely ever sees snow or ice.

curiously the tyre label for the crossclimate+ for fuel efficiency is labelled as B, where as for the energy saver it is C, which implies the crossclimate+ has better rolling resistance which doesnt make sense if the energy saver tyre is meant to be designed for efficiency

 

i find them to be smoother and quieter than the oems, similar mpg's and handling.

 

The official Michelin names are:

Energy Saver (summer)
Energy Saver A/S (all season)