tpete12

Greetings,

Over the past four years I have managed to average 27-29 MPG in a 50/50 mix of city and highway on the normal driving setting with regular unleaded, 30-31 MPG on longer highway trips. Fast forward Jan 2018 I swap out the original Bridgestone Turanzas for Michelin Primacy's after 60,000 mi and routine oil change from my local Toyota dealer and I've lost 5-6 MPG's on the last few tanks with the same driving conditions & routes. Not sure what to make of it. My first thought was possibly the dealer gave me conventional instead of synthetic by mistake. Would this cause such a drastic reduction? I also tend to think I've lost a little power/ jump off the start but this is less noticeable than the reduction in fuel efficiency.

I've also never pumped more than 14 gallons at the pump into the tank since the day I bought it. I know it has a 17 gal tank but I get shut off at the pump after 13.5 gal routinely when I run it until the gas indicator comes on (signifying one gal remaining correct?). These two have got me stumped when I regularly get 405-420 miles out of a full tank but with the recent reduction barely top 360 which is extremely noticeable. Thoughts? Appreciate any incite as I am not a car nut.

lesz

Have you checked to see if your tires are inflated to the proper pressure? If they are under inflated, that could account for some of the drop in fuel economy.

Has your area experienced colder weather recently? It the temperatures are around 30 degrees, for example, the fuel economy can be 25% or more lower than if the temperatures are in the 60-70 degree range.

Also, according to the ES 350 manual, the low fuel warning light comes on with 2.6 gallons of fuel left in the tank. In actual practice, I find that it comes on with somewhere between 3 and 3.5 gallons left in the tank. When the low fuel warning light comes on can be affected by whether you are driving on flat or hilly roads, how aggressively you are accelerating, etc.

I doubt whether the the dealer's service department would have not used full synthetic oil. Besides the fact that, right where the oil is put into the engine, it says to use full synthetic oil, Toyota and Lexus have been calling for using full synthetic oil with the 3.5 liter V6 for quite a few years, and any of the service technicians, by now, should be in the habit of using nothing but full synthetic oil in recent model year vehicles.

tpete12

Thank you - I'll check the tire pressure today. Temp swings have been frequent lately in Northern VA. Appreciate the info about the indicator warning that's more in line with what I experience too.

Poppa

Tpete.. I would guess that your drop in mileage would be attributed to your new tires. I know that all tires get rated as far as Rolling Resistance and it's not unheard of to either gain or lose a little bit of mileage when you change tires. By that I mean 1 or 2 mpg. Not 5 or 6. First thing I would do is check the air pressure in your tires.. make sure they're inflated to whatever the tire manufactuer recommends. I too have a 2013 ES and a little over a year ago I got rid of my Turanza tires.. I didn't get Michelins, I went with Pirelli's and haven't noticed any difference in my mpg since the tire change. Usually on a "long" road trip I'll avg around 30 -31 mpg, every once in awhile the computer will show me 33 mpg..... so check the air pressure and go to some tire web sites and see if you can find out any numbers for rolling resistance on your new Michelins... hope this helps.

Roland

Vegasaurus

Find a local, well-reviewed Prius mechanic. Stay away from chains or anyone that offers recharge or rebalance services.

Have them check the voltages of the individual modules inside the hybrid battery.

Edit: I can't read good. It's been a long day.

jgscott

iTrader: (1)

I thought he has a ES 350, not 300h? What the title says? I did find it on the high side to get average 27-29 MPG in a 50/50 mix of city and highway on the normal driving setting with regular unleaded? I don't get that. I drive more like 35% highway 65% City I get around 22mpg. I run Michelin tires also.

Not sure if this would do much but don't the Gas companies change from Winter fuel and Summer fuel mix's?

bc6152

The post is about an ES 350. I also have a 350 - for almost 6 years. I have never gotten above 24 MPG and I'm a very gentle driver who is retired and NEVER drive into the city.
I use the "normal" setting, have Michelins, and buy Costco gas exclusively. This would lead me to believe that the mileage computation of 27-29 mpg is a bit optimistic...

jgscott

iTrader: (1)

Ok. Post #5 mentions a hybrid battery, and finding a Prius mechanic?

jgscott

iTrader: (1)

Yea that's about what I get a little lower. If its the tires, I need to switch. The Eco setting does use less gas when I use it tho. But I like to drive the car it too much.

bc6152

The OP says an ES 350...

Turbofrank

2013 avg 24mpg here also

uncle

The same thing happened to me. I replaced Michelins with Sumitomos, and since that time, my mileage has dropped about 4MPG across the board.. It is hard for me to believe the tires make that much difference, but in my case, it did.
I like the Sumitomos, they are great tires.

JimInTN

Just purchased a '13 ES 350, w/ new Michelin tires. We live in a rural environment, so not as much stop & go/heavy traffic as larger cities, etc. We get 28/29 mpg overall but in our rural settings. We use the ECO mode 100% of the time, I was surprised at the throttle response and power in ECO mode. I was expecting the car to be very sluggish in ECO mode but am very pleased with. My SIL has a '15 ES350 and she drives in "city" environment, seldom on the interstate, and she told me she gets 25/26 mpg in ECO mode 100%.

I read somewhere on the web (gotta be true right) that new tires will drop mpg's a bit when brand new as the tread depth is at max, and the tire/tread will squirm as it rolls down the road but the amount of squirming will reduce as the tread wears out. Kinda of makes sense, but not sure I buy that 100%.

Albo

Really starting to question why I average only 20-21mpg on my 2015es350. Mostly suburban with occasional highway driving. I'd love to get those upper 20s. When I refill my tank full it estimates about 300miles on the read out

uncle

For what it is worth, for the first 48K miles on my ES350, I got routinely 33-35 MPG on the highway, driving at 75MPH. My best was 35.6. Since my tire change, I average about 29 MPG, same route, same speed, etc. My around town mileage was in the mid 20's, now in the low 20's. The only think that I did, was change the tires.