Is This All I Should Expect?

don't use the electric motor, where did you read that?

if you were only getting 40 mpg in good weather at 55 mph, there's something wrong with your car. but with 15 miles of 70 mph, that will hamper things. truth is, the hybrid system isn't that effective on the highway.

let's start with tyres, are they LRR? oil level? 12v battery health? air filter?

how many miles on her, has she hard all services performed? there are a couple that aren't in the book.

 

maybe you need to service some oddball things like the throttle body and maf, pcv and intake manifold, injectors and etc. just guesswork, but something is causing your low mpg's, although you're not that low, so it might not be worth the effort.

 

That is fine as long as you are not trying to force the car to use the electric motor when it would otherwise want to use the ICE (internal combustion engine).

Many people have this idea that they should run the car in electric to get the best MPG, but this is not the case. Due to energy conversion losses, it is more inefficient to force the use the energy stored in the battery. You are better off to allow the ICE to run in the 94+ to 49 MPG range. Allow the car to manage the battery to supplement the ICE. It is after all, a petrol vehicle with electric assist, not an electric vehicle (EV), albeit, a very clever implementation.

But I'm with Bisco, you should be able to get 55-60 MPG in summer and 45-50 MPG in winter, so something is wrong with the car, or the driver.

One other thing, how are you measuring your MPG? The the only reliable way is to record miles run and gallons used to calculate the MPG. Because of the variability of the fuel tank bladder, you then need to average the last three tanks (minimum) to get an accurate idea of the true MPG. Using the average on the consumption screen is very subjective. BTW, when was the last time you reset the average MPG counter?

I disagree with Bisco also about highway driving, with the qualification that after 65 mph it gets increasingly difficult to maintain an average over 50 MPG. But under that speed, there is no reason you couldn't (shouldn't) get 94 - 67 mpg (on the instantaneous MPG meter) for extended periods (on generally flat terrain). Use the DWB (driving without brakes) technique to anticipate the road/traffic ahead and you will see great results on the highway.

 

Yes, you should be surprised at the fuel economy. I have a used 2005 using cheapo non LRR tires. I drive all freeway except for the distance from my house to the freeway and my work to the freeway. (<1 mile) I rarely drive local otherwise. I don't drive slowly. I'm on the left lane going up to 85 mpg going up and down inclines. My commute is not flat. I don't use cruise control. I don't glide. I don't force EV operation. In short, I drive my Prius like I would any other car. I'm getting 46 mpg after 1 year of usage. In my 2006 Corolla, I would get ~36 mpg.

 

Light traffic will work in your favour, but if you need to slow down, disengage the CC early on, like really early on.

I think you'll be surprised the effect that will have. Seriously will change the Cd (co-efficient of drag) of the vehicle.

Remove it and only reinstall when you need to use it. Or, take the hit.

 

Only way to find out is to try it.

I don't reset the MFD. It resets on its own when I fill up. I find it's always optimistic 1-2 mpg. I calculate 46 and it shows me 48. There's no need to run the tank empty. You can fill up at half if you like.

Again, you don't have to try to get 45 mpg. If everything is working properly. That's what you get driving normally. When you try and hyper mile, you'll get 50 mpg and beyond. And if you do it incorrectly like forcing EV could also bring you below 45. As to why you're not at 45, I'll let the experts diagnose.

 

This is one of the problems when offering anecdotes in relation to a non-Gen II model.

The facelift Gen II (2006-2009) only resets the tank milage on the consumption screen when you fill up.

The first release Gen II (2004-2005) resets both the average MPG and the tank milage when you fill up.

 

At 70mph, you should be at least in the low 50s mpg wise. The Prius is however very sensitive to changes to its aerodynamics. I had the front plastic under-panel fall off on one of my trips, and even though it only sticks down about an inch below the other panels it covers, my mpg was very low for the 500 mile trip I did. When I did the same trip in nearly the same conditions with it repaired I got 5mpg better. Anecdotal, but it's clear the panel is important for the car's aerodynamics.

Therefore I'd say there's a good chance the bike rack could be causing a significant hit. Take it off and see if you get an improvement. A switch to low rolling resistance tires would also help.

Other things that could cause it are brakes dragging, bad alignment, clogged air filter, etc.

 

Holiday Hypermiling Seasons Greetings Corwin - As a Christmas gift to you, I have pulled a tweaked (by me) GEN II/2G version of some "Hybrid $mart" Driving tips from my personal "Hybrid Hypermiling - Hybrid EcoDriving - Ultra High MPG" web page for your consideration and edification.

"HYBRID $MART" DRIVING CONTRIBUTIONS TO AVERAGE MPG

Pseudo-Hypermiling/EcoDriving Pre-Operative Set-Ups:

• "Up-Pressuring" Tire Air Pressure [Plus: 3+/- MPG Gain going from 35F/33R to 44F/42R PSI running on the OEM Low Rolling Resistance (LRR) tires for 2G.
• Replacing Conventional “Dino” Oil with 100% Full-Synthetic Oil [Plus: 1.5+/- MPG Gain going from 5w30 “Dino” to 100% Full-Synthetic 5w30 for 2G].
• Engine/Drive-Train Break-In [Plus: 2+/- MPG Gain after 10,000+ miles].
• EBH and Grille Louver Blocking Insulation Foam (Very Cold Climate Ops Only) [Plus: 3 to 8+/- MPG Gain].
• Use of Federal and State mandated 90:10 E10 "10% Ethanol Added" Gasohol [Minus: 1 to 3+/- MPG Loss]

Pseudo-Hypermiling/EcoDriving Operating-Driving Techniques:

• Running HVAC From Fresh Air Vent Only Mode Through To Full-Time A/C AUTO Mode [Minus: 0 to 4-8+/- MPG Loss]
• Employing Acceleration Technique of iMPG ≈ iMPH/2 When Accelerating From Dead Stop Then Seamlessly Transitioning To iMPG ≈ 1.1 To 1.2 Times iMPH As Travel/Cruise Target Speed Is Approached [Plus: 2+/- MPG Gain in Around-Town/Mixed City-Highway Driving].
• Skillful Application of "Hybrid $mart" Freewheeling Coasting, Regenerative Coasting, and Regenerative Braking [Plus: 2+/- MPG Gain in Per-Full-Tank-Average MPG-FE for Around-Town/Mixed City-Highway Driving].
• Consolidating Shopping Trips/≤ 2-Minute Errand Running [Plus: 0.5+/- MPG Gain in Per-Full-Tank-Average MPG-FE for Around-Town/Mixed City-Highway Driving].
• Opportunistic Use of Advanced Fuel Conserving Warp-Stealth, Pulse & Glide, Dash & Coast and Super "Atkinson" Highway Mode [SAHM/SHM], Driving With Load (DWL) Techniques [Plus: 2+/- MPG Gain].
• Driving GEN II 2G at 66 MPH Fuel Economy “Sweet Spot” ECC Cruise Set Speed, rather than driving 2G @ 70-75± MPH during Open-Road/Interstate travel that is 99.5% Freeway/Interstate [Plus: 3.5+/- MPG Gain For High-Speed Open-Road/Freeway/Interstate Driving].

TOTAL POTENTIAL ADDED INCREMENTAL MPG CONTRIBUTIONS AVAILABLE FROM DRIVING A GEN II/2G "HYBRID $MART": 3 + 1.5 + 2 + (3 to 8) – (1 to 3) – (0 to 8) + 2 + 2 + 0.5+ 2 +3.5 = 8.5 to 21.5 MPG

RANGE OF PER-TANK-FULL FUEL ECONOMY POSSIBLE FROM DRIVING GEN II/2G "HYBRID $MART":

OFFICIAL EPA 46 MPG [Combined] + (8.5 to 21.5 MPG) = A "$MART" 54.5 to 67.5 Average MPG Is Possible

Important Fuel Economy Point To Ponder Is: Anytime the internal combustion gasoline engine is not running and you are moving down the road, you are getting "Infinite" Instantaneous Miles Per Gallon Fuel Economy. This "Infinite" Miles Per Gallon is displayed as 99.9 MPG on the Multi-Function Display (MFD). Conversely, if the ICE is running constantly, as the HSD may cause it to do during high-speed driving or in extremely cold, frigid winter weather operating conditions, the Instantaneous Miles Per Gallon Fuel Economy will converge on the 30-35 MPG fuel economy inherent to the ICE itself.

30-35 MPG (WORST) - YOU ARE DRIVING SOMEWHERE IN HERE - 99.9+ MPG (BEST)

 

Corwin, . . . You may want to read about the Gen II's bladder gas tank. With Winter's cold here, don't be surprised when the Gen II Prius takes fewer gallons at fillup time.

Enjoy your Prius, one of the best made cars ever.

 

Great suggestions by everyone but those Cooper tires might be a genuine part of the problem. Those same tires were on our current Prius when we purchased it in April. I immediately raised them to 38 front, 36 rear psi and we still only got 34.8, 40.6, 37.8, and 39.3 mpg on our first four tanks before we replaced them with LRR Pirellis (the Coopers were really worn anyway and needed replacement). As you can see from my signature we've raised the overall average to 43.0 since them and that's with very little in the way of special driving techniques. A lot of short hops around town kills the mileage while most of our highway driving is done at 70 mph.

 

Some of you guys are really optimistic about MPG.

My wife is the primary driver of our '08 Prius. She makes absolutely no effort to drive any differently than she has any other car. The car has Michelin Defender (LRR) tires inflated to 40psi, has service up to date (plugs, air filter, fluids, etc.) and no Thule rack. She gets 44mpg consistently in warm weather -- 70% highway @ 70mph, and 30% 2 lane road @ 55mph.

Now that winter's here, with studded snows it's 38-39mpg consistently. We're in Maine, so yes, it's cold.

 

i don't think it's optimism, just observation. different conditions will give different results. defenders and female driving will almost always result in low mpg's.