Changed spark plugs on Jan 11th. I do a good bit of driving early in the morning with close to freezing temperature weather. Is the mileage normal? Should I be buying a specific gas instead of Sam's club cheapest offerings? Would it be helpful to eat more tacos while driving?
Cold weather means lower gas mileage, so you'll see some fill ups in the mid-high 30s MPG. I'm in Minnesota, where it's been below freezing for most of the time since I bought my car last month, and my Fuelly graph is attached. It's pretty similar to yours, so I think you're fine.
I would change gas stations and pay a few more cents a gallon to get top tier gas. Over time it's going to make a difference. That cheaper gas may well cost you more in the long run due to additional maintenance and/or lowered gas mileage. There's a very simple explanation from the AAA and station list here: Buying gas from a station on this list is better for your car | Clark Howard
On that last tank, a quick calculation in my head seems to show you only went about 175 miles in a week. Are you going far enough to get it warmed up? That makes a big big difference.
That's absolutely correct, jerrymildred. When our Prius stays local it never gets a chance to warm up and be driven efficiently the way it was designed. Tanks have been known to drop all the way to 34 mpg occasionally as a result. It still gets 48-50 mpg when my wife has to drive in to Los Angeles to work. To follow up on my earlier post regarding top tier gas, I just checked local prices here. Higher rated Arco is only two cents a gallon more than Sam's, meaning at most only 20 cents a tank for the cleansers and additives protecting your car. Well worth it.
Today's top safety tip: when assembling tacos prior to driving, do not put the green chile on top. Place in bottom of taco instead, otherwise it could go in your eye in case of unexpected pot holes. P.S. I agree with using top tier gas when possible, especially if mostly using the car for shorter trips where the engine doesn't get a chance to get fully warm up. A tank or two of non-top tier is no big deal, but I believe that using top-tier gas will extend the life of the engine for most of us. First thing to check with low mpg is tire pressures, if you haven't already.
It won't hurt anything that I ever heard of. Some say it's a waste of money. Some say it has extra cleaners that help with economy. Since it does have more anti-knock agent, it will have a tiny bit less energy per gallon. I never bother with it, but some swear by it.
Nor.Prius - To give you some perspective, we just went and filled the car after 177 miles because we're going to be driving a couple of hundred miles tomorrow and I don't want to mess with it then. This 177 miles consisted of no drive longer than 4.8 miles in cool (by southern California standards) temperatures and rain. End result was only 33.58 mpg but I'm not worried. We'll get mid 40s to 50 mpg tomorrow on the freeway as we run to L.A., Orange County and back. Allowing the car to warm up and leaving it on makes a huge difference.
In the USA we would recommend TopTierGas.com stations which add adequate detergents in Regular. The way our US EPA regulates gasoline recipe here, there is not really an advantage anymore for Super here except for cars that need high octane. Years ago Super had better detergents here, but not now. You are overseas, so that means possibly different situation. Could be the Super has better detergents there. In so many words, the EPA regs made gaso a commodity here, without too much freedom for individual company recipes.
The short answer is no, as others have said. Additionally, you will receive absolutely no benefit from using super. If you keep records of your usage of "super" vs regular, you will see for yourself.
As expected, the mileage went way up yesterday. Spending almost two hours in rush hour traffic to L.A., an hour on the freeway coming back and the other running around the MFD is showing 147 miles and 50.1 mpg. Based on past history that means the car probably is between 47.5 and 48.5 mpg if I were to fill it up and do the calculation. How the car is driven makes all the difference in the world.
In London, there could be a MPG benefit for Premium (probably not enough to pay off). In the USA, EPA requires gasoline to be relatively low in higher octane "aromatics" to burn more cleanly. So that regulation basically takes some of the "umph" energy out of gasoline. Not to mention we then add 10% ethanol for even less "umph" re: MPG.
Thanks for the replies everyone. I've changed some things up a bit, and have had some things changed in my life since I first posted my question and got a few replies. First of which, is that since posting, I've been filling up with the best stuff my local shell station has to offer. I've also been driving less in the cold mornings, and it's been warming up a little bit. I've also started driving out to another city for work, almost every week. And those almost every week drives are coinciding with with the spikes in higher mpg averages. The drive is about 150 miles round trip, and I'll fill up when I get back into town. It's been a little while since I've checked tire pressure, I might do that today, and I'm aware that I need to change the oil in the next month here. Anything else I need to be aware of? Attached is updated gas logs. On a side note, i'm missing a blank "extra switch" cap that goes in the extra switch slots on the left hand side of the steering wheel (where the HUD brightness wheel is) so if anyone knows where I could get one, please let me know.
