Is my mpg acceptable?

[Crystal Shine]

Help.

2000 Boxster S manuel with 70,000 miles.

Steady freeway driving 67 mph without traffic. I could only getting 23.5 mpg.

Is my car something wrong?

[honda_nos]

I have a 1999 Boxster tip with 68k I only get about 18.5 MPG (mix city/hw)

Help.

2000 Boxster S manuel with 70,000 miles.

Steady freeway driving 67 mph without traffic. I could only getting 23.5 mpg.

Is my car something wrong?

[White987S]

Looks normal.

[70Sixter]

I be disappointed with less than 25-26 mpg in that driving mode. But nothing is dramatically off. Clean air filter? Plugs? MAF sensor?

Still , I would not worry. Some claim lower numbers.

[Glyn]

From a Brit point of view we would consider that a bit low, but when you consider your gallons are smaller than ours and i assume you are talking American gallons i dont think that is a dissapointing figure.

Especially when we Brits know all of you are on the large size ;)

And you were probably carrying your lunch with you :clapping:

[rick3000]

Thats seems about average, I've gotten up to 30mpg on road trips, but average about 20-25mpg city/highway. I wouldn't worry about it but you can always check your tire pressure, air filter, etc.

[ashleyisagirlsname]

I've got the exact same 2000 Boxster S (in Canada) with 37,500 mi and my car gets 26mpg at best. When I'm messing around in the city (i.e bouncing off the rev limiter I get about 18mpg) Like the old story goes, you have to pay the cost to be the boss.

An S2000 would have had much greater reliability and fuel economy, but at the end of the day you'd be driving a Honda, just like your neighbors in their Odyssey and 5 kids.

[1schoir]

Help.

2000 Boxster S manuel with 70,000 miles.

Steady freeway driving 67 mph without traffic. I could only getting 23.5 mpg.

Is my car something wrong?

It seems to be slightly on the low side, but nothing out of the ordinary. What is important though, is that you should monitor your fuel consumption as it is a good indicator that there is something that should be attended to if it changes drastically from what you have now.

Regards, Maurice.

[Peter in Reno]

Help.

2000 Boxster S manuel with 70,000 miles.

Steady freeway driving 67 mph without traffic. I could only getting 23.5 mpg.

Is my car something wrong?

What was your mileage before posting? Is your mileage decreasing? If this is the same mileage since you bought it, then I would not worry about it.

[White987S]

Crystal, I see you are in Cali. Do you run 91 or 93 octane? If you are only able to get 91 this could be "costing" you 1-2 MPG's too. Just a thought.

[stickshiftnz]

Appears to be acceptable. 23.5 MPG is about 9.877 km/L (10.13 L/100 km). Even with average cars like an A4 1.8 automatic or a Galant 2.5 V6, I could only manage max of 12.5 km/L (29.7 MPG) on a long drive. Remember that your car is not necessarily a featherweight, and it does have 6 cylinders.

Do you drive with the air conditioning always on? That can increase fuel consumption by as much as 20%. On the Audi and Galant, my average consumption for a week's combined city/motorway commute of 8.5-9 km/L (20.2-21.4 MPG) can drop down to 7-7.5 km/L (16.6-17.8 MPG) just by using the aircon constantly. Fortunately here in NZ, often you can get away with not using the air conditioner, I only use it when it rains (to defog), blistering heat after getting into the parked car, or at least 10 minutes every month including winter, just to keep the compressor lubricated. At times I will run the aircon for 5 minutes then off for the next 10.

[1schoir]

Fortunately here in NZ, often you can get away with not using the air conditioner, I only use it when it rains (to defog), blistering heat after getting into the parked car, or at least 10 minutes every month including winter, just to keep the compressor lubricated. At times I will run the aircon for 5 minutes then off for the next 10.

Invaluable advice for keeping the seals in the air conditioning system lubricated. Best insurance to avoid costly a/c repairs.

Regards, Maurice.

[White987S]

Fortunately here in NZ, often you can get away with not using the air conditioner, I only use it when it rains (to defog), blistering heat after getting into the parked car, or at least 10 minutes every month including winter, just to keep the compressor lubricated. At times I will run the aircon for 5 minutes then off for the next 10.

Invaluable advice for keeping the seals in the air conditioning system lubricated. Best insurance to avoid costly a/c repairs.

Regards, Maurice.

I would agree, but don't forget, whenever you turn on your front defroster, the A/C turns on automatically.

[70Sixter]

Crystal, I see you are in Cali. Do you run 91 or 93 octane? If you are only able to get 91 this could be "costing" you 1-2 MPG's too. Just a thought.

Hadn't thought about that, but I agree. No Boxster experience on 91. But Mrs Sixter's new X5 got 1-2 mpg less on 91 during Thanksgiving trip to NorCal. It also lost power that was especially noticeable going uphill. The transmission downshifted as many as two gears on hills that it held in 6th gear on 93.

[roger_mck]

All of the posts have been quite interesting - as I have recently been tracking my gas mileage using lower (cheaper) mid-octane fuel. I am not recommending this to anyone, but as for me, the change has been quite surprising, probably due to oddities in the fuel system (timing?) unique to my car.

Anyway I have a '99 non-s and have historically gotten around 21-22 all 'round mpg. The car has also had rather poorer acceleration at proper running temperature, a bit better when the engine was cold/warming. No dyno tests, just seat of the pants observation.

With recent high gas prices, I figured what the heck - let's try a lower octane fuel. Another change which coincidentally has appeared at most all of the stations in the area at the same time, is a switch to a 7pct ethanol fuel mix. To my surprise I now get 24.5 mpg and better acceleration at proper running temp. No downside as far as I can tell. I can't really guess why, but imagine there may be some oddities in the engine timing or operation of the fuel injectors which as a whole work out pretty well.

As for my around town driving habits they are quite boring about 95 pct of the time - above average use of cruise around town, like to keep rpms high until cruising, put the thing in neutral and coast at the mere suggestion of a red light somewhere ahead. The other 5 pct though... is pure fun!

FYI the most recent Porsche Parade magazine has a very good article describing the use of ethanol-mix fuels.

[fdmbautista]

Help.

2000 Boxster S manuel with 70,000 miles.

Steady freeway driving 67 mph without traffic. I could only getting 23.5 mpg.

Is my car something wrong?

Your mileage is pretty spot-on when you compare it to the EPA's fuel estimate.

http://www.fueleconomy.gov/feg/findacar.htm

Keep in mind that in most cars fuel economy drops drastically over 60mph.

[savowood]

In my 2000 non-S Boxster, I used to get around 28 on the highway and 19-20 in town. This was using 93 octane fuel. I've never used anything lower than 93. I would guess you'd get slightly better in the S, but you do have a bit more weight which may negate that.

Currently in my Boxster, I get about 22 in town (18-19 if I've been playing) and right around 30 on the highway. However, this is with a 3.4l Carrera motor from a 996. YMMV

-Michael

[Guest carpediemgr]

Hi and happy new year to all

Michael from Athens Greece own 2.5 boxster with 43000 km

9.8 L/100km in highway using 4 and 5 gear and accelerate to floor

18 -30 l/100 km in the city of athens need many times to stay 5 minutes without moving a step ahead :)

lucky Europeans :) i use 100 octane superunleaded casoline lol the power of 100 octane make the car more economic because of the better acceleration

thanks michael

[stickshiftnz]

OK -- 9.8 L/100 km = 24.3 US MPG highway, and 18 - 30 L/100 km = 13 - 7.8 US MPG (yes, in L/100 km, lower figure is better) urban for Michael from Athens.

[matthewjamesdunn]

Was the top up or down? Just my 2 sense but I would assume the car is more efficent with the top up (lower drag configuration). Apples to oranges but my Wrangler (not quite as aerodynamic as my Box) gets significantly lower mileage on the highway with the rag down.

Matt

[Bill_SoCal]

Help.

2000 Boxster S manuel with 70,000 miles.

Steady freeway driving 67 mph without traffic. I could only getting 23.5 mpg.

Is my car something wrong?

Hi Crystal,

I'm just inland and south of you in Temecula. I drive a 2003 Boxster, manual, with 107,000 miles. I've driven the car since it was new off the lot with 17 miles. I know many people have a fluctuation in mileage, however, I drive to San Diego daily without traffic at about 75-80 and I ~29 mpg. As a matter of fact, I drive on the freeway so much that I've never even done rear brakes to my Boxster yet. I follow the Porsche maintenance schedule for all other service. I drive in the morning with the top up and generally with the top down in the afternoon. Based on information from http://www.fueleconomy.gov/feg/maintain.shtml, if you have a dirty air filter, that could cause a degradation to your fuel economy by up to 10%, low tire pressure could impact your mileage up to 3%, and the incorrect viscosity engine oil could cause further degradation of 1-3%. I know my mileage is accurate as I calculate it at almost every fill up. Seems low to me based on your driving habits.

Good luck! Every improvement helps these days with the cost of gasoiline.

Best regards,

Bill