Lousy Gas Mileage

[quicksilverdon]

Originally Posted by b1ken

I know the car is boxy but my daughter owns a Toyota Matrix which she claims gets well over 30 mpg. My friend has a 2006 Hemi Charger and he claims the thing gets 30 mpg. say whaaaatttt!!!!! The thing supposedly runs in the 13's so this is REALLY pi$$in' me off!

I run into that all the time. I find that individual tankfulls have widely varying MPG - due to the particular cutoff of the gas pump you fill at. I record every drop of gas I put in, and I think the only accurate measure is over several thousand miles.
I find most people calculate mileage only every now and then, and remember the highest one. They often do it on a long trip, which is typically when you get best mileage (as opposed to stop-and-go).
I am at 55,000 miles, get just under 25 MPG overall. I check tire pressure regularly, "coax" the auto into high gear as soon as I can (accelerate, then lift off the pedal and feel it shift) and if I see a red light ahead, foot comes off gas pedal. Acceleration is what eats gas - I go over speed limit, just take a bit longer to get there.

As to the syntheic oil/dino oil test - how many dyno runs were made? I think you would get a 5HP variation on a 500+HP engine with back-to-back runs with no changes - that's only 1%!
I'm a believer in syntheic oil - I had a '92 Dodge Spirit that sucked in a valve guide at over 150,000 miles. The mechanic had the head on the workbench, and where the camshaft was was all clean and shiny. I asked what he'd used to clean it up, and he said that's the way it was! Whether synthetic gives better mileage I can't comment on, but to me, it is well worth the incremental additional cost.

As to premium vs regular - some cars can adjust timing up to the onset of pre-ignition - I think the PT only retards, not advances timing. For a non-turbo engine, it's set for 87 octane. If it detects pre-ignition, it'll retard timing, but I don't think it will advance timing to take advantage of higher octane. I run my turbo lite on regular.

[bados]

I have on '05 GT. I use a K & N filter and since going to Mobil1, picked up .5 miles per gallon taking me up to about 20 average driving highway and city.

[b1ken]

I'd agree that a 4 HP loss (529 to 525) might seem to be within % error for a dyno but I noticed a lower torque reading that was obvious. This dyno is not computer controlled and requires you to read torque & rpm from the gauges. I manually adjusted the water brake. The tests were definitely repeatable within 1 HP. The point was that while maybe I couldn't document an exact loss, there was certainly no gain. As to my gas mileage, I'm pretty careful about filling the tank and I average 20-21 mpg with the 2002. I definitely don't lead foot it, use cruise control any time there is 1/4 mile of straight road ahead and don't tailgate. In short, I drive like the old fart that I am. I save my acceleration shots for the drag strip with my Super Gas car. My friend, with the Hemi Charger IS a heavy foot, though. That pig weighs 5000 lbs. (I think). 30 mpg??????

[Turbodude06]

well my 06 PT/GT only has about 4,800 miles on it so its not broke in yet and I live in Georgia were its hilly as $hit here, and I'm 19 years old so I probably drive harder and faster then most of u, no offense, and I don't get any less then 19-20 mpg around town, and I've gotten 25 before, but I have a 5 speed which I know if u drive right u can get much better fuel mpg, but I still complain about it cause I'm used to my civic which gets 34mpg when I'm not even trying for good MPG, but my exhaust helped out alot so I would get that first and if you don't have a turbo get that Tornado its lik $59 bucks but it really does work its not really worth it though with the turbo motors its pretty much the same concept.....

[cappy5]

Hi Guys, I don't know if our Australian models are tuned different but the last time I checked my mileage over at least 6 tanks full I averaged 29.2 mpg running on our unleaded,octane 91, the manual says not to use premium unleaded,octane 95. I tried the E10 fuel ,octane 94 I think, which has 10% ethanol and it gave about 1.5 mpg worse and seemed to have a miss every so often. My driving is about 65% at about 70mph on the highway and the rest is driving to work at about 65mph for 16miles each way. I use aircon all the time and on the highway I change from 5th back to 4th to pass semitrailors[single ,doubles and triples ] as quick as possible.My PT is a stock standard 2006 Ltd 5 speed with about 19,000 miles , I don't abuse it but I make it work when necessary.My last car was a Commodore sedan,auto and 3.8l V6 which gave near the same mpg,had more power but was no where near as comfortable and as much fun to drive, plus the PT stands out for being different.Happy Cruising,Cappy5.

[quicksilverdon]

Yes, Cappy, Ethanol, while it has a higher octane rating, contains less energy, so mileage will be poorer.
Is your engine 2.0 or 2.4L? You also probaly have a manual, which is much better for mileage.

[cappy5]

I forgot to mention that I have a 2006 PT LTD 5 speed,2.4 litre motor.I was wondering if the big differences in fuel mpg,apart from driver style, is due to fuel grades,I found this in WIKIPEDIA [Regional variations
Octane ratings can vary greatly from region to region. For example, the minimum octane rating available in much of the United States is 87 AKI and the highest is 93. In the Rocky Mountain (high altitude) states, 85 octane is the minimum octane and 91 is the maximum octane available in fuel. The reason for this is that in higher-altitude areas, a typical combustion engine draws in less air per cycle due to the reduced density of the atmosphere. This directly translates to reduced absolute compression in the cylinder, therefore deterring knock. It is safe to fill up a car with a carburetor that normally takes 87 AKI fuel at sea level with 85 AKI fuel in the mountains, but at sea level the fuel may cause damage to the engine. In some east coast states, up to 94 AKI is available [4]. In parts of the Midwest (primarily Minnesota, Illinois and Missouri) ethanol based E-85 fuel with 105 AKI is available [5].

California fuel stations will offer 87, 89, and 91 octane fuels, and at some stations, 100 or higher octane, sold as racing fuel. Until 2003 or 2004, 92 octane was offered in lieu of 91.

Generally, octane ratings are higher in Europe than they are in North America and most other parts of the world. This is especially true when comparing the lowest available octane level in each country. In many parts of Europe, 95 RON (90-91 AKI) is the minimum available and the standard, with 97/98 being premium or "super" (except Italy, which hasn't adopted it because of its pollution) [citation needed]. In Australia, "regular" unleaded fuel is RON 91, "premium" unleaded with RON 95 is widely available, and RON 98 fuel is also reasonably common. Shell sells RON 100 petrol from a small number of service stations, most of which are located in capital cities. In other countries "regular" unleaded gasoline, when available, is sometimes as low as 85 RON (still with the more regular fuel - 95 - and premium around 98 available.) In Russia and CIS countries 80 RON (76 AKI) is the minimum available and the standard]
It also had about Ethanol having about 1/3 less energy, no wonder my PT didn't like it compared to our 91 octane fuel.
Cheers,Cappy5

[fritz_t_coyote]

Cappy: Are you still using Imperial Gallons in OZ?

[cappy5]

Hi Fritz_t_coyote,I completely forgot about US gallons being different to British gallons, In Australia we are metric, it was imperial when I was younger so I'm used to both so I converted to imperial for this forum .My last fuel check over 3540km's[2212miles] was 10.38 km/litre which is 29.2 miles /british gallon where-as I should have put 24.6 miles / US gallon. That seems to compare better to other members PT's. This discussion has sure shown a heap of variables in fuels and figures. Cheers,Cappy5.

[Oso73]

I put in an Air Raid kit about two months ago and noticed an increase of a couple MPG plus more pep. I run the tires at 39 lbs all around (the max rating is 44) and that helped a bit plus it handles better. I get 23 - 26 MPG with combined city and highway driving communting 18 miles one way everyday with about 10 on the freeway. I use cruise whenever I can and try to avoid mashing the pedal to the floor. I took a trip using mostly backroads averaging 50 - 55 MPH two weeks ago in mostly flat or slightly hilly country of Ohio/Indiana/Iowa and achieved nearly 29 on the average, that's actual computed milage, not the trip computer.

Heck my SRX gets nearly 26 MPG and it goes a heck of a lot better the the PT. I'm going to try one of the spacers from Air Raid plus freer flowing exhaust next spring. I used a spacer on my 350 Chevy pickup, with headers, dual exhaust, K&N drop in plus Mallory coil and 10 MM wires with platinum plugs and cruising @ 62 mph burning 91 octane got over 22 MPG. Before the mods I was in the middle to low teens. I'm hoping the same will work on this 2007 TE non-turbo. Keep on cruisin'!