A typical passenger car runs at 1,500-3,000 RPM unless you’re on the Autobahn at 130 mph. A NASCAR runs at 8,000-10,000 and uses a fuel rated at 105 octane (I think) for that reason. The same for airplane fuel, where a skipping or knocking engine can mean stalling and death.

Best,
Renee

AHEM…. not true The desire to accelerate under full throttle thing. Its an expensive hobby.

I’ve got dibs on this userid here. I’ve registered it in the GRS Forums.

In previous comments, I recommend losing a few hp to save a few $s and use 87 octane.

How about in order to avoid “Ian” looking dual personality, you add a letter to your name?

Cheers, your namesake (Ian)

There IS a reason to do so. If the owners manual requires premium that means that the car was tuned to run best on premium.

However many newer cars have knock sensors that will prevent pinging if you use lower octane fuel. The downside? You’re not getting all the power your engine is capable of. But since most of us (and probably all of us here) never accelerate with full throttle the lower power will never be an issue.

Just check first to make sure your engine has a knock sensor (your owners manual should say something about it). If you are using too low a grade of gasoline and your engine is regularly pinging, you are slowly destroying your engine, and the cost to replace it will certainly outweigh the cost of premium (which is typically only 5-10% more).

And just for reference I was an engine calibration engineer with one of the big 3 for 3+ years.

My advice? Check your manual to see if you can run regular gas.

You may want to research the difference between premium and regular grades of gas. Ever since I heard the guys on NPRs “Car Talk” say that there’s no reason to use premium, I’ve used only regular in our family’s Volvos and Volkswagon and have not had a problem in the year I’ve been doing so.

You should be fairly confident on the readings coming from your cars computer. The only thing to caution is that you need to make sure you are using the correct tire size for your vehicle. Installing larger tires or going with a low profile version will skew the readings the computer is providing. It also could jeopardize your tansmission in the long run.

That’s not too far from what I do. Though I don’t even like using the camera. I just use the recorder feature on my phone. Press record, say the miles, gallons, and cost/gallon. Then later (sometimes a couple weeks later) I’ll listen to the recording and put it into Fuelly.

This should also help to get my wife to keep track of the data on her car.

Good luck, Ian

TS

Thanks for linking to my article!

The site helped me save $120 per year, which in itself is minimal. But as I elude to in the quote you posted, the savings from decreased engine and transmission wear may be far greater, however unquantifiable they are.

You seem to be right on target for all three cars, congrats!

I also want to highlight one thing that some readers may not pick up on: cost per mile. You mentioned it, but then can lead to better decisions/routing.

MLR

Here in Finland, when we get our driver’s license, we have a whole lesson dedicated to economic driving and learn about how to shift gears and rev the engine properly in order to save gas.

The general idea is that you dump all your savings into a single account in order to earn the most interest and then use MyMvelope.com to portion those savings in individual envelopes so you always know how much of the lump sum is for what.

We use it to save for non-monthly expenses like clothing and car services as well as holidays and desire purchases. We also use it to help teach our kids about saving with their pocket money – they each have their own “box of envelopes”.

http://mymvelope.com

Wanna take it even further? use public transportation! You basically amortize the energy used by the bus/train between hundreds of people or more.

I know that these solutions don’t work for everyone, especially in suburban areas, but maybe rellocating to an area where you don’t need a car just to buy groceries, or even better to get to work, is something worth considering.

I forgot to mention that when I was going to school at PSU, I figured out how to drive all the way from one side of downtown to the other (S to N) without EVER stopping at a stoplight!

Give it a try the next time you’re downtown. If my memory serves me correctly, the magic number is about 14.5 mph.

This cheap little beater didn’t have a trip odometer, so I recorded the mileage and fuel pumped from the very first tank in a journal. Not only was it a great way to track gas used, but I found it helped me identify mechanical problems early. If the steady ~27mpg of my dear old clunker suddenly dropped to 24mpg, it always meant there was a problem.

I now drive a hybrid that displays fuel consumed instantly, but I’m still in the habit of writing it all down at each fillup. It’s great to plot my mileage over time, see how seasonal variations impact the MPGs, and keep an eye on the health of the engine.

And it’s neat to have a first-hand record of how the gas prices have fluctuated over the last few years!

I have been using mpgtune.com for over a year. Fuelly looks to be a nicer site than mpgtune.

I used to track my fuel efficiency (the old fashioned way – pen and paper) with every fill up for many years. I was addicted to tracking it. Then one day somebody asked me why I bother. I had no answer, so quit tracking. It was so freeing to not worry about writing down my fill-ups any more. Damn mpgtune got me hooked on tracking again.