Any Data on Tire Inflation Benefits?

Overinflating does lower the rolling resistance of Avid S33d tires and it can help increase a Prius' FE but you won't see much of a boost in FE unless you are driving on dry smooth roads, you drive between 20 mph to 38 mph to minimize wind resistance, and you drive longer than 50 minutes per trip. Michelin Energy Savers are suppose to have lower rolling resistance than the Yokohama Avid S33D but the advantage is only incremental. A Prius ICE needs to warm up to over 130F before it can glide. To efficiently do a pulse and glide session/cycle the Prius ICE needs to be about 180F/ Hence, the longer the Prius is running the more FE it becomes. Unlike the 2nd gen Prius, the 3rd gen Prius doesnot have a coolant heat recover system so while it uses thermal energy more efficiently it will loses thermal energy much more quickly after it is turned off when compared to the 2nd gen Prius.

Running a Prius nonstop less than 2 miles/4 minutes returns very low MPGs, e.g. less than 20 mpg. Running a Prius nonstop greater than 16 miles/60 miles a trip can deliver really hi MPGs, e.g. greater than 50 mpg.

The details can be overwhelming but overall if you are driving a Prius , no matter how badly it is driven, the Prius will still likely be getting better overall MPG than most other vehicles out there on the road. It is not because the Prius is so much better but because most of the other vehicles are so much worst.

 

You can also see the effects of road surface if you can monitor tire pressure or better yet tire temperature.

My other car has TPMS with a dashboard pressure readout. I have seen tire pressure go up one or two psi when driving on rough chewed up concrete after driving on new smooth asphalt. Tire pressure goes up a nominal 1 psi for every 10F in temperature increase, so the pressure increase I observed was the extra work being done on the tire by the road.

 

I disagree with your assumption that 44 psi is sidewall normal. The last few sets of tires I've bought have all been marked 51 psi max. I'm actually hesitant to buy 44 psi sidewall tires.

I'd assert that the majority of the people on those forums running 45-51 PSI are actually running at or below sidewall max just as I am.

 

I put 100k on 3 sets of Michelin ES's, on my 09 Jetta TDI (sold). I kept them at 50 psi, gained ~ 2mpg. I am currently having all of my dental fillings replaced. No issues with wet/dry grip, but didn't really push it in this regard - driven conservatively.

 

Thanks again, Walter.

Driving time is not an issue for me as my daily commute is at least 47miles one way.

I upped the tire pressure to 50/48psi from the 40/38psi they were at. If the ride is no worse than the same pressure in my old dB Super E-Spec tires on my GenII then I may keep them there. If the ride is too harsh I'll drop back down to 46/44psi.

 

Ok that didn't last long. I went to the grocery store at the 50/48psi setting and I didn't like the rougher ride so I lowered the tires to 46/44psi.i normally wouldn't mine the roughness but I think I've already been spoiled by the cushy ride of the stock 2012.

I'm going to call Yokohama tomorrow and see if they would be willing to work me out a special deal on the new AVID Ascent and trade in these AVID S33Ds. With all the publicity I try to give them I would hope they would throw me a bone. lol