2010 Prius 38 mph on trip 42 back...

For starters, please answer as much of this questionnaire as you can: Fuel economy complaints/queries? Please copy, paste & answer these questions, esp. if you're new. Post the answers here.

Also, how long have you actually had the car, and what were the weather conditions during your road trip?

 

Yes, more info. would definitely help as we don't want to assume too much. BTW, welcome to Prius chat.

 

Well right off the bat, the tires u bought (although I don't know too much about them) are not LRR tires & probably not comparable to the oem stock tires it originally came in which could make a big difference in MPG. In addition, the pulling is a sign that u need alignment & should be done asap. Plus, all tires need a break-in period after new to be optimal. Another thing which I'm sure u know of is that A/C kills mpg., so if possible, use only when needed but being u live in Arizona & it is summer time, u probably need it most of the time. Lastly, excessive speed hurts mpg alot as well. So, if u were consistently over 70 mph on the trip to Cali, plus w a/c & your current tire setup, I can understand the mileage you're getting. But no worries, achieving the mileage that u stated is very doable as u may have to make some adjustments & corrections such as the alignment first. One step at a time, you'll get there in no time.

 

ElleMarie - these are my following suggestions given the information you provide about your driving conditions:

If the Prius has to stop because of a upcoming stop sign avoid going too fast - keep the Prius top speed low enough such that by the time the Prius ends its gliding phase at the stop sign it is travelling less than 15 mph.

The Prius is using a bit more gas to keep the Air Conditioner going - you can help by:
1) Tint your windows (AZ=tint laws are pretty generous :33% tint for driver's side windows, and no restrictions for the rear side windows/rear window)
2) Get a heatshield sunshades to keep the Prius a bit cooler (so you won't have to work the AC so hard).
3) Set the Prius to ECO mode because it help runs the AC efficently

A things that might help the FE.
4) Increase tire pressure to 40 psi front 38 psi rear
5) Get the wheels alignmnet
6) Avoid driving over 70 mph, high speeds causes a Prius' fuel efficiency to drop ( FE speeds = 25 to 50 mph).


Review the Prius' Maintenance Schedule
1) What is the Prius odometer reading? (miles)
2) when was the last time the Prius' oil and oil filter was changed? (date/odo miles)
3) when was the last time the Prius' air filter was changed? (date/odo miles)

A more detail review of your driving environment.
4) what is your top speed that you drive at? (0mph...110 mph)
5) What is the approximate percentage of trips done by the Prius that is less than 5 miles (0%..100%)
6) How many bars are normally on your HV Battery SOC HSI display? (1-8)

 

Some items have already been addressed, I may repeat a bit:

Well, you need AC, but do you really need the coldest temperature setting? This car can be quite comfortable with much higher settings, e.g. 76-82 instead of LO-65.

Those 3 miles trips are going to hurt MPG due to engine warmup (even in your climate), and to initial interior cooling. Longer trips thin out these penalties out over more miles.

The impact of the many stops will depend strongly on driving style, which can improve with time but may be constrained by other traffic, especially if it is aggressive.

Dealership 12V battery checks are notoriously worthless on the Prius. It is better if you have or can borrow a voltmeter or Scangauge.

The 12V battery should not yet have aging problems, but this car had a few more bad ones from the factory than normal, and some others get drained / damaged in ordinary use, sometimes even on the new car lot.

Brand new tires always hurt a bit until they get broken in.

I'm not familiar with the tire brand, but it seems unlikely to be a Low Rolling Resistance model. That will also hurt a bit, maybe 2 mpg? Maybe one of our resident experts, such as F8L, can chime in.

Changing out new tires just for better MPG is unlikely to pay off. Keep them for their regular tread life.

Is that tire pressure in the morning, before the first trip, and with the tires not in direct sunlight? If so, good. But if they have been heated by driving or the sun, there is still a chance they might actually be low. Re-check in the morning.

Somewhere around here is a chart of MPG vs. speed, without the penalties imposed by engine warmup, climate control, and weather. It will tell you the best you can get at any given speed, without a downhill slope and without a tailwind. It is enlightening.

The 45 speeds can produce very high MPG on longer city journeys. But engine warmup hurts on short trips, even in your hot weather. Sitting a long time at lights doesn't hurt in my cooler climate, because my AC is off. But it will hurt in your climate when the AC is blasting, as the constant drain on the traction battery must be replenished.

 

My friends have pretty much covered it above but I'd like to add onto their thoughts and recommendations.

Your tires are probably as bad as you can get for mpg. They are an Extra Load (XL) tire and sport a 91V rating. That is way more than you need on a Prius when a nice Standard Load T rated tire would do. This basically means the tire is likely designed for high speeds and handling, not for fuel economy. You could be losing as much as 4mpg or more just due to tires. If so this would put you around 46mpg if you had OEM tires or even higher if you had the best LRR tires. This is somewhat speculation since I have never even heard of those tires.

Running the A/C will definitely hurt fuel efficiency. Period. Now, the degree to which it will hurt depends on a few factors. When you first startup the car and it is 85F+ you will suffer a 7-10mpg hit until the cabin cools down closer to what you have your AC setting on. If you set it to 65F it may never cool to that temp unless you are making a long trip of 20+miles! Once the cabin does cool down, the AC compressor will draw less energy and the mpg hit may drop to 2-3mpg depending on outside temperature. So you could be losing quite a bit of fuel efficiency from this alone. A 5mile trip with the AC set at 65F means you are running the entire trip at -7mpg or more. Do this enough times and you can see how your mpg will tank. Ask the folks in Texas what their mpg looks like right now after a bunch or short trips.

You're likely stuck with the tires unless you can swing a deal with the dealership for putting crappy tires on your car. Get them to swap out the tires for a good LRR tire if possible. Otherwise you're not going to get the advertised mpg without trying harder. If you cannot get new tires then Keep them inflated like Fuzzy said.

I would recommend setting the AC at 76F and seeing if that helps any. Try to combine trips so the car doesn't cool down too much between stops otherwise the AC will have to use a bunch of fuel getting rid of that heat. See my thread about AC use for other tips.

How to Reduce MPG loss Because of A/C Use | PriusChat

 

btw by heatshield sunshade (for the front windshield) I meant something like this...
PriusChat Shop : 2010-2012 Toyota Prius HeatShield Sunshade - Front [1215] - $32.00

One thing I forgot to mention is that you may want to double check with the person maintaining your Prius about its oil level and the type of engine oil being used - from what I understand if the Prius MPG will drop if 1) the oil level is too high OR 2) if 0w20 synthetic oil is not used.

F8L is correct - the Accelera 651 195/65r15 appear to be made for hi speed hi load/excellent traction on dry and wet roads -they do not appear to be low rolling resistant tires and probably reducing your MPG by about 5 mph. It's sort of an expensive proposition to swap tires but since these tires are relatively new you could probably get a signficant amount of credit on them if you swap them out now. However, unless gas prices shoot up into the stratosphere - swapping to LRR tires is not going to save you any money. SoCalBPrius correctly points out that after about 10,000 miles of tire wear - your tire's rolling resistances will naturally drop so you might just want to just over inflate your tires a bit more hold out until then for that slight MPG boost .

One thing I didn't mention previously was *wearable* driving gear - because the OP appeared to be primarily focused on the Prius and not the driver/occupants. In extremely hot weather conditions some hypermilers wear a "cooling" vest which keeps the wearer cool in extremely hot weather so they don't have to turn on the AC ( Hypermiling guru Wayne Gerdes is known to use one). Most "cooling" vests consist of an adjustable insulated vest with pockets that are filled with flexible thin gel ice packs along the torso area ( These are mainly for employees working in very hot environments, e.g. welding. Most gel pack units work for 3 to 4 hours). The most affordable cooling vests use a sponge like material that absorbs water instead and cool the vest by water evaporation (These are mainly designed to be used by construction workers). Most expensive "cooling" vest have *active* cooling systems and can be worn underneath other clothing ( They are mainly are designed for altheletes who have to keep cool. For example, an althete with a medical condition like MS where the muscles tend to overheat too rapidly would benefit from wearing a cooling vest ). These "cooling" vest weigh between 3 to 8 pounds - so they aren't all that lightweight, they can be a bit bulky, and some can be very pricey (+$300/each) but they do work. The following is a nicer intro...

ActiveMSers: Staying Active With Multiple Sclerosis

 

ElleMarie – Responders to your question, Walter Lee, F8L, Fuzzy1, & SoCalBPrius, shared some sound advice and thoughts. Let me offer some of my thoughts in response to your “Any thoughts?”

You say “it was involved in a sideswipe that was fixed and then the vehicle was ‘certified’ so don’t ‘think’ that is an issue.” To this I will say, there are “sideswipes” and then there are “SIDESWIPEs.” Gentle “sideswipes” only involve cosmetic type, non-structural related repairs - No Problemo with this level of collision damage. However, “SIDESWIPEs” involve structural repair requiring realignment of the unitized body “Cage,” which can leave a car, even a “Certified (i.e. within spec)” car, with tracking and alignment “Issues.”

For the sake of this discussion, I will assume your new, used 2010 Prius has no such “tracking and alignment ‘Issues” or a failing 12v Accessory Battery that are negatively impacting your MPG numbers.

If you have “watched videos, read this forum and have been working so hard to drive ‘Prius friendly’,” then it is likely that you are already mostly driving “Hybrid $mart,” rather than “Hybrid Dumb.” Based upon this assumption, I assess you as being a “Certified Prius Borg Queen.”

Taking your Prius Borg Queeness as a given, if you were driving in optimally “Hybrid Friendly,” Prius “$weet $pot” operating temperatures and highway terrain and road conditions, you could nominally expect to see Per Tank-Full MPG numbers of 110%-115% of Official EPA Fuel Economy. This would deliver around 54-56 MPGs in the “Around Town” travel speed potions of your driving, and 49-51 driving on the “Open Road” at 70-ish MPH.

So where might you be loosing MPGs with you operating away from optimal “Hybrid Friendly” conditions, which would contribute to giving you your current, lower than "expected-hoped for" 38-42 MPG numbers?

Running at 38F/38R PSI on the new, non-LRR Accelera tires, in combination with not running the tires at an Up-Pressured 42F/40R “Cold” PSI, could be COSTING YOU 2-4 MPGs.

You may or may not be running with 0w20 Full Synthetic Motor Oil. Not having Full Synthetic Oil could be COSTING YOU 1-1.5 MPGs.

Running the HVAC From Fresh Air Vent Only Mode Through To Full-Time A/C AUTO Mode is good for a “Hit” to your fuel economy ranging from 0.0 to 4-8 to 10 MPG. With you operating there in desert hot, sunny Phoenix, AZ, my guess is you running the A/C Full-Time, which is probably COSTING YOU 8+ish MPG.

Doing the math, considering just these three (3) areas of loss off the optimal 49-51 MPGs to 54-56 MPGs fuel economy in your AZ-Driving, yields 49-51 to 54-56 MPGs MINUS 11-13.5 (2-4 + 1-1.5 + 8 = 11-13.5) MPGs, which yields a range of 34-38 MPGs (Low-End/Worst-Case) to 43-45 (High-End/Best-Case).

Your 38-42 MPGs falls within this range. Up-Pressuring your tires to just below MAX “COLD” SIDEWALL SPEC PSI, assuring you are using 0W20 Full-Synthetic Motor Oil in the engine, and running your Air Conditioning thermostat set in the Mid-70s °F w/ moderate air blower fan speeds, will help work you towards higher MPG numbers.

Additionally, further refining your driving techniques will add incremental MPG Fuel Economy. Try making yourself “Hybrid $marter” with skillful application of Fuel Miserly Driving Techniques. Techniques like:

1. iMPG ≈ iMPH/2 Accelerating From Dead Stop,
2. "Hybrid $mart" Freewheeling Coasting, Regenerative Coasting, and Regenerative Braking,
3. Consolidating Shopping Trips/≤ 2-Minute Errand Running,
4. Opportunistic use of Advanced Fuel Conserving Warp-Stealth, Pulse & Glide, Dash & Coast and Super "Atkinson" Highway Mode [SAHM/SHM], Driving With Load [DWL] Techniques, and
5. Driving at the 71 MPH Fuel Economy “Sweet Spot” ECC Cruise Set Speed for the 2010-2012 3G, rather than at 75-80+ MPH during Open-Road/Freeway/Interstate travel.

Work on your Pre-Operative Set-Ups and applying and/or perfecting-honing your Hybrid EcoDriving Techniques, and you will start logging those “but I was hoping for the high forties” MPG numbers you are expecting and hoping for, as well as possibly seeing “Bonus MPG Numbers” up into the low-50s MPG Per Tank-Full Fuel Economies.

I invite you to click on, read, digest, and put-to-practice my "10 Hybrid Basics & Best Practices Tips Guide To Prius Ultra High MPG" in my signature.

 

Very nice job! on the article!

One thing I will add when I bought my new 2005 Prius, I't took me between one and two years to really get to feel the car and to kind of become one with the car (sounds kind of dumb, but), after about 15 months I noticed a real nice increase in mileage all of a sudden, almost like magic!

 

ElleMarie - Thank you for "Liking" my e-babblings. I hope they serve to help you gain the "$tellar" MPG-FE numbers you are seeking.

retired4999 – Hum-m-m…Let me see if I can “Break The 4999 Code.” If retired4999 breaks out to 4/9/99…April 9. 1999, then I would have to retort with retired112000…1/1/2000…January 1, 2000.

Anyhoo, thanks for the “Kudos” on my “Ten Tips Guide…” article. As I say and forewarn, its 16,000+ words tend to be overwhelming at first glance. However, there is a golden mega-nugget of information or two or three or…???...in its textual banquet buffet, which can help bump up the Per Tank-Full Fuel Economy numbers of most budding hybrid fuel-sippers beginning with their next fill-up.

Your 2005 2G Prius was an outstanding training platform for you in preparing to operate your new 2012 Prius PIH for MAX MPG. Yes, it certainly is a wonderful feeling when you enter the ZEN ZONE, and become a fully-assimilated Prius Borg Drone and regularly start racking up “$tellar” MPG-FE in both fair weather and foul.

I started driving a 2007 2G Prius in the Fall of 2006. I came to it with a Porsche-honed Throttle Pedal Foot. I quickly became fully-assimilated into the Prius Hybrid “Hive,” and, shortly thereafter, achieved Hybrid Guru “Water Walking” status. I piloted my 2007 2G at a solid 125%± of Official EPA MPG over the lifetime of my ownership. I traded it in, with 60K-miles on it, for a new, 2012 Prius v Five Wagon w/ ATP.

I find the Prius v Wagon to be a Euber-Prius, “Caddy In A Kimono.” In my opinion, Toyota discarded the worst features and traits of the 2G & 3G while bringing together the best features of both into the Prius v (vee). They did everything right, thereby, producing a single fuel-sipping platform with great OEM instrumentation, oodles of driver and passenger seating space and comfort, and a 50% increase in cargo-hauling volume.

As I say, Prius v…"v" for more "v"ersatility. Roger that…but also…"v"ery good driver road perspective "v"iew "v"isibility, "v"ery good fuel economy, and "v"oluminous interior space.

I am currently operating our Family Limo & Stuff Hauler “v”onder “v”agon at a solid 125% of its 44/42/40 EPA MPG, with excursions up to 130% of EPA, and some summertime A/C Use induced MPG dips down to 120%. I fight hard and drive “Extra Hybrid $mart” each driving day to gain back incremental MPG lost by chauffeuring and keeping my COLD A/C Lovin’, estrogen-fueled Prius Borg Queen Bride-For-Life, Wife, at the COLD-COLD-COO-O-O-O-L-L…cabin temperatures Her Highness Nibs desires.

On a “Cents-Per-Mile-Total-Cost-Of-Fuel (Energy) Basis,” I am currently expending 5.6¢ worth of “Black Liquid Arabian Gold” motor fuel for every mile it takes me and mine to electro-glide down the highways and beachside byways here on the Space Coast of Florida.

This Enquiring Prius Borg Mind Wants To Know. On a ”Cents-Per-Mile-Total-Cost-Of-Fuel (Energy) Basis,” between “donations” to your local Gas Station and the Eau Claire Electric Cooperative, how are you doing with your Prius PIH (PIP) during hot, hot, triple-digit hotter Summertime Ops up there in “America's Dairyland - The Badger State?”

 

I really don't crunch the numbers much, But on this tank of gas I have driven 1600 miles with four bars of gas left.
It cost about 10 cents a kwh to charge, so about 25-30 cents a charge so far 285 kwh from EEC and about 53 gallons of gas, total of 4,300 miles average about 80 mpg. First 4 tanks of gas all hwy to get it home no ev. last two tanks lot's of ev. Plug-in just fine in hot weather no problems at all, keeps me cool too at same time!

You sure know how to spin a good yarn!

Thanks for the laugh!

 

very impressive on a "vee" wagon. I'm @ 7.5-8 cents per mile on my prius but that's based on $4 avg. gas price which I'm more than happy with.

 

I think your AC use is a reason for low mileage. Try putting it on Auto and 76-78F, and most likely you will be comfortable, while mileage will increase.
Best,
- Alex

 

SoCalBPrius – Thanks for “Liking” my petrol pontification to ElleMarie. You are correctomundo in advising her that Tharz More MPG Gold In Dem Thar A/C Temp & Fan Settings.

I checked out your photo album. Your Blizzard White “Benzin-Sippin’ Beasty” looks great with the Llumar charcoal Tint riding on those Drag 17" DR-34 Wheels. 7.5-8 cents per mile on $4-Plus Per Gallon gasoline at 49% City/51% Highway split in a 3G is great “Petrol Warfighter” performance.

I am running my Pv5ATP on the OEM 17" Alloy Wheels w/ P215/50R17 tires Up-Pressured to 51F/50R with their inherent “MPG Hit” versus the more "MPG Friendly" OEM 16" Alloy Wheels w/ P205/60R16 tires on the Two & Three version of the vee. Current local gasoline prices here in Paridiso Florida are down to the $2.969 to $3.039 range. However, I am having to “Hump Hybrid Hard” on my Pv5ATP Warfighter to keep its running MPG numbers up, thereby, keeping it electro-gliding @ 7.5-8 cents per mile.

Since my 2012 Pv5ATP was purchased new in Fall 2011, this is my first summertime of operating it. I am currently operating it in daytime OATs of Mid-To-High 80s w/ Hi-Humidity. When I am able to run the A/C in my vee set on AUTO 75°F w/ 3-BARS ON BLOWER FAN, that cooling setting has noticeably and measurably less drain-impact on my running AVG MPG, as compared to when I put it to AUTO 71°F w/ 7-BARS ON THE FAN (MAX BLOWER), in response to Her Royal Nibs requests for an extra pulse of cooling.

I am still taking data, but my current anecdotal “MPG Hit” data “snapshot,” comparing running at “AUTO 75°F w/ 3-BARS FAN” versus running at “AUTO 71°F w/ 7-BARS FAN,” is that those 4°F Extra Degrees Of Cooling & 4-Extra Blower Fan Speed Notches are nominally worth about a MINUS 4-MPG “Hit” on a Per Tank-Full Average Basis.

I too am quite happy with maintaining both the summertime Nickel-Plus Cents Per Mile and Low 50s Per Tank-Full MPGs in my Prius vee Wagon, especially, considering it is being propelled by the same 98 hp 1.8-Liter 2ZR-FXE "Atkinson-Cycle" I4 as the Prius 3G Sedan, and is having to move 232 extra pounds of chassis through an increased, less “MPG Friendly” rear axle ratio with a 16% increase in the Coefficient of Drag.

OUCHY OUCH, Toyota! Talk about tying one’s EcoDriving hands behind their back, and then asking them to log Official EPA Beating, “$tellar” MPG numbers.

 

Great news! You're on your way now & will never look back to the initial bad mpg u had.