It's been only a couple of weeks since I bought my 2012 Prius2. Have already made a couple of long trips from LA to Indian Wells ( Palm Springs ) and back. On my first trip I got 53mpg going down and 49 mpg on the return and I was elated to say the least. On the last trip I was not so fortunate....49 going down....and yes I was bit lead footed.....before starting back home I had to replace my left passenger tire due to a blow out, side wall damage. I had to install a new Yokohama Avid Touring S, instead of the stock S33. MPG on the return trip dropped to 38 I can only deduce that the low MPG was due to the the new tire that had a different tread pattern than the other 3? I will be replacing the Touring S with the stock S 33 tomorrow, but my concern is that I have 18k mile on the other 3 tires. Should I replace both rears in order to have 2 tires with equal amount of tread, or will it really matter? Would hate to fork out another $150. Your advice/ comments will be greatly appreciated. Thank you.
assuming you bought it used and didn't put 18,000 on in a couple weeks? 18,000 is almost half the treadware, so you probably should get two new tires and keep the old one as a back up. onthe other hand, the rears don't wear that fast and tread depth measurement is more important than mileage. i don't think that would account for a large drop in mpg. if that is your only concern, replace one and see how the mpg's are before replacing the other.
If you can only deduce that then you need to use more imagination Seriously, there are many variables that play a part in your mileage. - The new tire will offer more rolling resistance until it's been broken in a little. - Do know if the tire pressures were the same before and after? It's not unusual for a tire dealer to adjust the tires to what they believe to be best--they may have deflated all tires to the Toyota recommended level, which is a little more comfort-related than thrift related. - I doubt this is the case, but were you driving on wet pavement? More drag from that, to be sure. - Did you use air conditioning more on one trip than another? Not a big hit, but could add to other factors. - What speed were you driving on these legs? If the same speed, trip to trip that can still play part in my next question... - What was the wind speed and direction on these trips? While a 10-15 mph wind might not be noticeable in your daily driving, on a long trip it can cost extra fuel if it's working against you. To my point above, the drag becomes very significant at higher speeds. If you're driving 70 mph into a 15 mph headwind the car's got to work much harder pushing the air around. - Are your mileage calculations from the on-board display or by calculating from odometer readings and fill-ups? I'd be positively surprised to see 53 mpg if you were driving 65-75 mph--48 mpg would be more likely. It's possible to have your fill-ups vary by how full the tank is filled and in this mileage range a 1/2 gallon more or less makes a big difference in your calculations. Things to think about...
Thank you for the feedback. Yes Bisco I did buy the car used with 17.5k on the clock. I will start by replacing the tire, since I am going back to Palm Springs next week I will be able to make a fair assessment of how the car performs with just one new tire. css28, thanks for your insight, you make a good point about tire pressure, I took it for granted that the folk at Americas Tire would have known to make sure the pressure was up to Prius specs.... I will check and adjust. As for the other variables you touched on, I did mention that on my second trip I was a bit lead footed, the AC was on during both trips and I was on dry pavement on both occasions.... The only variable was the wind factor which along with the tire pressure may have been the cause of the drop in MPG. I am looking forward to see how the car behaves next week when I make the same trip. Will keep you'll posted. Thanks again for your input.
I assume you were driving on I10. As you know, they have all of those wind turbines once you get past Banning. Those wind turbines are there for a reason ... it gets really windy there and gusty. I believe the general direction of the wind is that it is at your back when going east on I10 (but it can swirl, too), so you got better gas milage going to Palm Springs. Plus all of those hills can cause some havoc, no matter which way you are going. And I think American Tire would have lowered your tire pressure on both tires to about 36PSI (which I believe is recommended PSI stated on the door jam) rather than increase it to 38 or higher. I'm not sure you can get any consistent MPG along that freeway near Palm Springs, going in either direction. Mike
The original tire is Low Rolling Resistance. The Touring S probably isn't. At max sidewall I swapped out my OEM tires at 60000 miles. The lower the pressure, the faster the tire wears.
I did make my way down to the desert against last week after replacing the the mis- matched tire. I did get an average of 48MPG and am quite happy. Tire pressure was set at 41 front and 40 in the back. Mike, you are right, you do have a tail wind going and strong headwinds on the way back on interstate 10. On Saturday I did a 100 mile round trip ( mostly Fwy) on cruise control set at 68MPH and averaged 51MPG....Sadly on the way out the car was hit by something small that flew out from another vehicle .....the stone, pebble or whatever, hit the RHS quarter glass and shattered it! Hopefully I will be able to install it myself. Need to buy the replacement window today. Thanks again for all of your input.
I would check your tire pressure on all four tires, before you start replacing them. It may make a different in your overall MPG.
Another trip to the desert this week. MPG"s bacp up again. 55 MPG GOING DOWN WITH STRONG TAIL WINDS. 50 MPG ON THE RETURN TRIP... TIRE PRESSURE WAS SET AT 41 in front and 40 in the back. I am a happy camper!
