New Owner!!! ONLY 38MPG

The two obvious things sticking out are the tires (I don't believe these are Low Rolling Resistance (LRR) tires) and that you are running the A/C full blast (if it is similar to the gen III, setting the temperature to LO = full blast). The tires might account for 3 - 4 mpg. The A/C on full might account for anywhere from 5 - 10 mpg.

F8L did a quick video showing the impact on instanteous MPG when the A/C was running hard and it was about a 10 mpg drop. As the car cools down, the MPG hit will be less as the A/C doesn't work as hard.

But I agree, I'd expect 45+ mpg if I was keeping my top speeds to 60 mph and my trips were 25 minutes. The top speed limit will allow for very adequate freeway MPG (55+ mpg) and the 25 minute trips will offset the poor mileage shown in the first 5 minutes. Try setting your temperature to 74F and see if your mileage improves. You'll probably want to get the life of these tires, but realize you are trading fuel efficiency with tires that likely perform better in handling and stopping distances.

 

Hi Farias. You've got the "touring edition" which has slightly larger wheels and which most people (for whatever reason) report a few MPG less with (compared with the stock standard prius).

I agree with codyroo that you're probably losing a few MPG with those tires. There's a bit less choice in LRR tires in that size, but there's definitely much better available than what you've got.

Re the A/C usage. If you get a more humid type of heat in your location, try setting the A/C temperature fairly high, like about 75F, and just the drop in humidity will keep the cabin comfortable enough.

 

Just like any car, if you adjust your driving style, your mileage will go up. What were you driving before and what kind of mileage did you get?

 

Sigh. This answer provides no information. Many times, we have had people say the 12V is "good", when it was really bad. Give us real numbers, like 11.X at Ig-On. The value of X is important!

Also, 51 psi is high for tire pressure, even if it is the max sidewall limit. You'll not see much of a MPG difference between 51 or 42 front/40 rear, but the comfort should go way up.

Further things to check: Does the engine turn off when you come to a stop? Do you have a roof rack or anything else that would disrupt the aerodynamics?

 

Hi Farias1109--

The biggest things that stick out to me are the touring wheels, the tires, tire pressure, and California.

I've also got touring wheels and it can put a real dent in your highway mileage, although it doesn't matter nearly as much in the city. I have to work hard to get any 60+ highway segments and that's by barely holding 55 MPH, sometimes dropping slightly when going up hills (52, etc.). On the plus side, your car can be easily distinguished from a Prius with standard wheele.

With regards to the tires, I agree with codyroo and uart - LRR tires would help here. With tire pressure on the other hand, I have to respectfully disgree with the others. I firmly believe that PSI = MPG, and I believe everyone should press up their tires to the maximum pressure listed on the sidewall.

I can't officially recommend you go over sidewall, but I can personally say I run mine at 60 PSI, which I may lower because if I keep it up I'll damage my spine before long. I've driven in a Prius with the tires as high as 80 PSI before without any ill effects except the TPMS light being on and the CD player skipping every time you hit a bump. Tires can take a lot more than we give them credit for, but mercifully it wasn't my Prius - or my tires I was paying for.

Lastly, living in California means you get CARB-compliant gasoline mixtures - since they banned MTBE a while back, the only way to get the fuel oxygenated enough is to add ethanol to the fuel. E10 in my experience with the 1NZ engine series can cost you up to 15% of fuel economy

 

It may be obvious, but that could be added to the questionnaire.

 

If you could give us some idea of what to expect in a Touring at 60 mph, for 40, 50, at 60 psi, tat would be helpful. I personally did not find any benefit from running mine over 42, but I have LRR on 15s.

 

When I had my 2008, I found that my speed had a lot to do with my mpg. Like you I ran air conditioning all the time. My average was 44.4 mpg over the six months. http://www.fuelly.com/driver/southerndad/prius. I tried several different things to increase mpg. I did have the low resistance rolling tires.

I did successfully get higher mpg on a few tankfuls, but I'm too lazy to use the coasting method for long. I'd suggest checking out different ways for your commute. Maybe the terrain is part of the issue.


iPad ? HD

 

Second the speed, anything over 62mph is going to drop your mileage into the 40's, I also suspect the 12v battery, if the ice is running to charge a low battery @2amps, that's a lot of gas wasted.

Clean your interior air filter, check your engine air filter, check your oil level, make sure the emergency brake is functioning properly and isn't binding the rear brakes, front wheel bearings ok?

 

Hi seilerts--

I'm pretty crushed on time over the next few days but I'll run a test of some kind later this week and I'll try to establish a decent set of controls in order to determine the actual mileage differences. My experience is largely limited to my prior vehicles: I do know I was getting under 50 MPG highway at 55-60 MPH when the tires were at 32 PSI all around, and now I'm closer to 60. But I'll keep you posted.

 

Hey bro I had the same problem with my 2013 prius after 120k miles the milage went down. I changed oil air filter spark ⚡️ plugs . Tire pressure and everything. I found that it was the fuel ⛽️ injectors bought an STP fuel injector cleaner put it in my gas tank and I boosted my MPG from 38 to 50 mpg.
I normally have a lead foot and my commute to work is 27 miles there and 27 miles back with many hills. my mind is blown. The cleaner was only 4 dollars but it save me way more.

Recommended usage is once every oil change dude.

 

Definitely...tire choice will help. I run only Bridgestone Ecopias. at 45 psi. Clean Spark plugs and fuel injector cleaners as well as a new air filter and a clean hybrid battery Fan go a long way......

 

I saw a large improvement with a set of refurbished injectors from ebay for about $40-50. The cleaners eventually stopped working, even the professional clean at the dealer, eventually I had a faulty injector causing an engine idle shake and after swapping them out I was getting 50+mpg for the first time in a looong time. The cleaners with PEA at least helped remove carbon from the combustion chamber. But it is the clean spray pattern of clean injectors that really helps MPG from my experience.

 

My wife's prius is running a bit rough and I have been using Marvel Mystery oil and fuel injector cleaner which has helped. I've read the manuals on the process for changing them out. Unsure about removing the valve cover gasket. Will I need new gasket seals? The vibration isolators are supposed to be replaced. There are 4? Any good videos on this process? I have a 2008. OEM injectors are $150 which isn't bad. as I'd rather do this job once. Any good advice on doing this job?

 

I think I followed a Youtube video, but I didn't need to remove the valve cover. I tired to blow out any debris or dirt on top of the engine around the fuel injectors to prevent to much from going into the cylinders. Canned air works if you don't have compressed air.

I bought 4 refurbished injectors from ebay for $40-50, great bargain. But $150 for OEM isn't bad if that for all 4.

The hardest thing was disconnecting the fuel pump, and that was easy when I found a way to do it at the driver kick panel and not touch anything in the rear of the car (some cut access holes in the body under the seat, I wanted to avoid that). So you just have to pull the lead from the wiring connector and reconnect the connector.

Then the fuel rail can be disconnected from the fuel line (quick disconnect), the rail then passes through a cast alum. loop/hole in the block, and I think that is why they say to remove the valve cover as that would open that cast hole the fuel rail goes through. So I just left valve cover on and rail in the hole and used that as the hinge point for when the fuel rail pulls off of the injectors. The tightest one being the next to that hole/hinge point since the rail has minimal swing near the cast alum. hole. Not the factory procedure but it worked and got it back together quickly.

The injectors just pull out after that, once new injectors go in you want to lube the rubber seals with fuel, and gently hinge the rail back over the closest injector seal then each one in series as the rail engages each as you move to the left, away from the cast alum. hole hinge point. Then you can hook up the fuel line again, but you might want to wait for the gas smell to dissipate before you connect the fuel pump wire. You may need someone else without the fuel smell in their head, but you want to use you eyes and nose to look for any fuel leaks and check over the next few days smelling to be sure you are back together correctly.

 

I don't see any problem

 

I guess the OP must have thought the same thing ten years ago, as he did a "one and run" post. LOL

 

I live in California and I drive 2009 Prius with 200k. I bought it a few years back at 160k. I average 30- 35mpg but I drive very fast and do very short trips under 5 miles most of my driving for last 4 years.
Here is my opinion what contributed to poor gas mileage.
1. Driving very short trips leads to poor mpg.
Any thing less than 10 miles each time you start your Prius. So if you drive 5 miles to the gas station and turn off your car and start up a second time to do 5 more miles back. This is not consider a 10 miles trip but 2x 5miles trip. Everytime you start up the Prius you'll notice the 1st 5 minutes is always the worst mpg. It's because the hybrid system cycle and ICE needs time to warm up to the correct operating temperature to be the most efficient mpg. I noticed my mpg would get low 40's when I was driving over 20 mile commute each way. My longer drives would get high 40's once the Prius never went over 55 mph. 55 mph to 75 mph low 40's to high 30's.
2. Lead foot driving hard and driving fast all ways kills mpg. I can see a 10 mpg difference when I drive slower and not flooring it from light to light.
3. Putting in correct gas helps too. 87 octane is recommended by Toyota for normal sea level altitude. I noticed a big mpg increase when I take my Prius out of states that don't uses any ethanol additives. My mpg increase 15% better gas mileage. If california used pure gas I know my Prius would average low 40's even with my lead foot.
4. Keeping tires inflated correctly 44 front 42 rears. Also buying LRR tires helps but All seasons don't hurt that much maybe 1-5% lost of mpg.
5. Roof racks and cars mods decrease the mpg too. I know a lot of Prius owners lift the Prius 3 inches to help with bottoming out and dirt roads. This drops the mpg 5-10% miles less.
6. Poor maintenance, over due oil changes, dirt air filter and using wrong oil definitely affects mpg.

Even at 38 mpg thats good results for a car that can fit 4 people comfortably. I would say nothing is wrong with Prius and due the factors I outlined and results may differ from driver to driver and Prius to Prius.

SM-A526U ?