Subaru B9 Tribeca - Real World MPG Numbers

kmartin

Tell me what really is the danger of filling up to the brim?

I was referring to the practice of running almost OUT of gas first, and then trying to get to a filling station on fumes. My dad used to do that in his patrol car, and always bragged that he could drive on fumes...until the day he finally did run out of gas in the middle of nowhere, which happened to be a quarter mile form his aunt's farm house We still raz him over that.

-Karen-

PS, and for the record, I usually fill mine to the brim to, but I rarely ever need more than 13 gallons or so.

ateixeira

I ran out of gas in my Miata. Not fun to push it along for a block or so (and I was lucky).

Now I fill up when I'm below 1/4 tank.

-juice

jim314

It's OK to fill until auto shutoff, and even to top off after that (but not right to the top of the filler neck) if (1) you then drive the car a significant distance and consume enough fuel to bring the level down, or (2) if the outside temperature is cooler or colder than the temperature of the fuel in the supplier's underground tank.

If you have the filler handle on automatic and at a high flow rate, the gas will foam up into the filler neck and may shut off the pump when the tank could take up to another gallon. It's OK to top off as long as you don't truly overfill to the point of damaging the fuel and emissions systems.

The volume of the fuel compared to the capacity of the tank will decrease significantly as it cools in cold weather and will increase significantly in hot weather. Damage to the emission system is most likely to occur if you would fill the tank to the top, drive a short distance, and then park the vehicle in a hot parking lot for long enough time that the fuel in the tank would heat up and expand.

I don't have the full story on the following, but I'll give it the way I rememeber it. I have read that the filling stations are allowed by law to advertise the price of fuel by volume of fuel at a standard temperature, something like 68 deg F.

In Canada for most or all of the year the temperature of the fuel in the underground tanks can and will be significantly lower than this and this fuel would be measurably denser than it is at 68 deg F. So if you accurately delivered this fuel by volume the customer would be getting more weight of fuel than agreed upon and in Canada the oil companies have gotten an agreement that they can setup the pumps to give a lesser volume of the cold fuel such that this would be the correct volume at the standard temperature.

But in most of the US averaged over the year the temperature of the fuel in the tanks is slightly warmer than the standard temperature and the oil companies have not wanted to make a temperature correction and federal laws on this reflect the wishes of the oil companies.

jensenly

Thanks to all who posted on this topic. I just got my Tribeca 2 days ago and this was the one BIG question I had after reading the owner's manual.

bgunit68

It states in the owners manual that you shouldn't top off and to use 93 octane. We have had our Tribeca for 2 years June. We have 60,000 miles on it. Now we either get average 19 mpg or 16 mpg. Depends on who is driving. I was told recently the new Tribeca has a lot of changes. The front is different. They have more horsepower and you can use regular unleaded fuel instead of high octane. Someone asked earlier if there was a difference in performance using high octane. Absolutely. Also, we just had front end work done (clunk) our dealer rented us a new Tribeca. Our car has 60K on it and it is as smooth and tight as the new one. I just purchased Michelin Synchrone Tires for it. I am a very happy Subaru Owner. Even with the first year quirks.

morey000

Thanks for your 60K-mi report. Not too many 'beca's out there that have been 'broken in' yet. Keep us posted on it's progress.

occking

Just turned 37k on my 06. Since I have had the vehicle early August last year (got it as a demo with 10k on it) per trip computer have averaged 21 mpg. Probably 3/4 highway driving. Maybe it is because no more winter fuel (live near Providence, RI) or the car more broken in than it was last summer, but interesting the gas mileage the past few weeks, in which I have done more "running around" but no long trips, mpg averaging a little over 18. Last year with similar running around no long trips less than that. So maybe it is finally "broken in"???

My biggest complaint is still the very harsh ride I get in the vehicle. Like no other new vehicle I have had in many years. Had the bushings replaced recently for the lower control arms, but that did not seem to improve the situation at all.

bgunit68

There has been issues with the front end. I have experianced one at 25k and 54k. But they repqired them. I think it is one of the smoothest and quitest rides I've ever had.

morey000

I've found that the ('07) 'Beca absorbs larger bumps extremely well, but you feel every little pebble. My guess is that a different set of tires might help. When I was younger, I used to really like this "road feel" in my sportier cars.

anyone with experience on changing tires? The stock Goodyears are not rated all that highly at TireRack. (although they last a long time)

bgunit68

I just replaced my tires at 55k. I got the Michelin Synchrone 4 X 4. I really like the tires. Maybe a little louder than the LSII's. But boy that car can handle a turn! I got mine at Discount Tire Direct. Tire Rack charges shipping Discount Tire doesn't. I just bought a used Sport Trac from the same dealer. But I thing in another 2 years I'll buy another Tribeca.

cptplt

I put Nokian WRs on my 06 after just 600miles,didn't want to hassle with the TPMS sensor in winter when putting on snowtires. The Nokians are as nice as the Goodyears in the summer, dry and obviously much better in the snow being snow rated. Had lots of success with the Nokians on a Windstar as an all year round tire and seems to be the case for the Tribeca too.

schmoo3

A simple calculation of the increased MPG on premium will show you that it's basically a wash - and better for your car to be using at least 91. I got my B9 at 18000 miles and used 91 or higher (usually 93 as that's what most stations have) and consistently got 24mpg. Last year to try and cut costs as fuel went up, I used mid-grade, 89, and dropped the mpg average to 20; 21 very careful driving. What I also found is that the majority of the gas is used to get the thing going, but once up to 30 mph it rolls nicely as the stock tires have a low rolling resistance. It's actually fun after a fill up to go really easy and watch the MPG rise - I took a picture as we got it to go over 30mpg crawling along easily and steadily on a 45mph road! Beyond that, turn off the AC climbing hills and use the hypermiling techniques.