lexusman08

Have any of you tried overinflating your tires to improve fuel economy, especially on the freeway. What were the improvements? There are "Hyper-miling" forums sprouting up providing tips on extracting the most mileage from a gallon of fuel and many have had amazing success. The one drawback is a harsher and noisier ride. However with quiet and smooth vehicle such as the ES, I wonder if noise and ride would suffer as much.

Lexmex

I have done this for many years in my RX300, including when I lived in Mexico, but only did this after having my tires filled with nitrogen. Currently, my tires allow for a max of 44 psi and I use 38 psi, when they should actually be probably around 33 or so. You do have a harsher ride (and I installed new shocks in January) and I'm not sure with the ES that you'd particularly like it, but you will save a bit on the gas mileage, maybe about 1 to 1.5 mpg.

Dave Mac

Actually I've improved my gas mileage almost 20% with some of these hyper-miling techinques but have kept my tire pressure at no more than 2 psi over the recommended pressure to presrrve the ride of my ES. Anything more than that and the harshness is just too much for me. I get most of my improvement from controlling my starts, acceleration and looking ahead to stoplights. I still drive the same highway speeds as I always did although I have observed that knocking 10 mph is and easy way to boost mileage. Even after doing this for six months it still takes almost constant vigilance to keep from reverting to my old ways.

Dave Mac

BillP

While increasing tires pressures near max inflation can yield a mile or so per gallon increase on the highway there are downsides to doing this. Most probably any reduced fuel cost will be outweighed by premature tire wear. A significantly over inflated tire will wear the middle of the tread area faster requiring the tire to be replaced sooner verse a properly inflated tire. So across the life of ownership there could be an extra set of tires required. At $500-600 for a set of tires the reduced fuel consumption will not compensate that expense. Less contact on the road can also reduce traction in an emergency situation.

RX469

iTrader: (1)

I go approx. 2-4psi over recommended just to add a little more cushion for the rough roads and potholes.

kroze

you'll definitely need more cushion with ford probe, I heard they'll give you bhg from the slightest road bump

rpmathews

All,

I've been 'hyper-miling' my ES350 since I got her used about 2 months ago. I have a 50 mile round trip to work everday. I run the tires at 35 psi, not too harsh, awesome highway ride and using cruise control always on the highway, I average 28.5 MPG. The ride is 60% highway 40% city.

Awesome Ride, I traded a Acura TL for this car and would NEVER think about going back!!!!


Rob
'07 ES 350

fly2m51

I run my ES350 35psi all around and get a great ride I know someone who puts 40 in the front since more weight is on the front tires and 35 in the rear and they say it helps with tire wear and gives a great ride too.

safford197

Is everyone talking about sacrificing safety by over inflating tires to save gas in their $40K luxury car?

I get great gas mileage but I must admit that was the very last thing I considered with this car, actually thinking back to the time of purchase I don't think I checked it purposefully, it was one of those things I saw in the window when the sales guy went to get the key, just by accident I saw it. I suppose if I really wanted the gas mileage or needed to save the cash I would have opted for a camery hybrid, same size, similar 0-60 time, cheaper price, nice options, cheaper base price. I would have considered the Toyota version of this car had it come with a V6 hybrid.

Cheers,
Paul

toneman

I don't know what Camry Hybrid you were looking at, but I'm pretty sure that the majority of Camry Hybrids out there do not have 0-60 times that are similar to that of the ES 350--high-8 second range vs. high-6 seconds (conservative) for the ES 350. Not unless you consider 6 and 8 second times to be "similar"...

Back on-topic--I'm sure you folks know why overinflating tires helps improve fuel economy (however small an improvement may be achieved from doing so)...increased tire pressure reduces rolling resistance of tire by reducing the size of the contact patch between tire and road...reduced rolling resistance/smaller contact patch means less friction/resistance between tire and road...which results in better fuel economy.

sirCharles

2 psi bump up works for me. Especially if you ride solo.

safford197

It's 6.4 vs 8.3 seconds and ~18% and gas is >20% so the trade off is pretty fair. I'll admit it's a very noticable difference but still the hybrid has a good time for 0-60.

MARINE

I usually ride at max pressure. I get around 20 combined. I never was ever able to control my lead foot.

fly2m51

Now Lexus fills all tires with nitrogen, One it doesn't expand and contract with a temp change, two it doesn't carry water like O2 so it cuts down on corrosion. If you use Nitrogen your tire pressure sensors are less likely to go off like they do with air. They say it extends the life of your tire.

dreyfus

There's a lot of nonsense being thrown around considering nitrogen in tires. Unfortunately, there is some here, and being a former chemist who worked daily with nitrogen and liquid nitrogen I'm compelled to say something about it.

First, nitrogen gas does expand and contract just like air (or any other gas or gas mix). This is just the laws of physics. The ideal gas law doesn't care what type of gas it is.

Second, while nitrogen is definitely less corrosive than air, what are we corroding? Your aluminum wheels don't corrode in nitrogen or air so unless you're running on steel rims there is no difference here.

The claim that nitrogen is better for your tires is probably due to this reduced reactivity with the rubber compounds. While true, don't almost all tires wear down & out before they fail chemically?

Third, nitrogen holds every bit as much water as air. However, nitrogen is usually pumped from cylinders received from the supplier and these have a very, very low moisture content. Air is pumped directly from the air and most setups don't evacuate the ambient moisture. So filling you tires with air on a humid day will put more water in your tires than filling them on a dry day. So nitrogen is better in this regard only because it's dried before dispensing, not because it's inherently drier. Put a good moisture trap on an air supply and it will be just as dry.

Another claim for nitrogen is that it's a bigger molecule and therefore won't diffuse through the tire as quickly as air. While true, air is 80% nitrogen already so the difference is likely to be negligable.

All this to say that nitrogen's benefits are probably overstated, but not entirely without merit. If given the choice between air and nitrogen I'd take the nitrogen. I'm just not going to pay extra for it.