Lousy Gas Mileage

[b1ken]

Hi, Everyone. I'm new to this web site and I'm sure this question has come up before. I own 2 PT's (2002 & 2007). The 2002 averages about 21 mpg (Long Island - flat terrain), which is O.K. (I guess) but the 2007 (Florida) seems to be around 15+ mpg. I don't have a heavy foot (I mean, what's the point - these things are slugs anyway) and I use cruise control 80% of the time. I have seen where some people claim they get upwards of 30 mpg but I really ain't buying that. Before you get insulted with the "slug" remark I'll say I love these things, but performance isn't one of their attributes. I drive an NHRA Super Gas car which goes over 160 mph in the 1/4, so not too much feels fast on the street (not even the 480 c.i. hemi that I built for my friend's '70 Challenger). Anyway, does anybody out there have any tricks besides tire pressure for getting better mileage? I really believe the cam timing should be advanced, because this engine has NO low end torque but runs O.K. if it's revved past 3000 rpm.
Ken B.

[tpsfoto]

Wecolme to the site...I too am from Long Island ...Plainview....
I have a 2005 GT Turbo with about 600 miles on it .....I am easy on the pedal & am getting 16mpg....I would love to know how to do better....I put a K&N air intake & no better mileage....just a bit more pep....

Larry

[Hooligan]

I have a 2006 Limited, and also got bad mileage until I had about 1,000 miles B4 I started getting better mileage. At 500 miles I noticed a miss. Replaced plugs and wires. I now have 36,000 and have always checked mileage at each fill up. On one section of a 3,500 trip I did get 30 MPG, usually runs 24-27 highway, 17 -19 mpg around town. I to, have a heavy foot. I have the Airaid air filter and Bassani catback duals, that is all I have done to her.

[dolemite]

I'd recommend going with a K&N air filter. That plus:

-inflating tires @ 38 rear/40 front
-Mobil 1 5w30 & K&N oil filter
-resetting the computer (disconnect neg. battery terminal 5 min.) 4 or 5
times over the last month
-trying to keep RPM's no higher than 2500
-popping it into neutral when I see a light change to red up ahead
-Crane FireWires & Bosch Platinum 2 plugs

..got me currently up to 24-25 MPG in town.


The RPM's are probably the biggie.

[cruisinbabe]

....but what about gas? I have a 2006 TE and I'm using an 87 octane gas.

would it make any difference if I used a higher grade, say, 89 or 91?

[Mean Green]

Originally Posted by cruisinbabe

....but what about gas? I have a 2006 TE and I'm using an 87 octane gas.

would it make any difference if I used a higher grade, say, 89 or 91?

Your car is already tuned/programmed to use 87. Going higher will do nothing, in fact you would get poorer mpg. The PT is a slug, weighs too much and is a brick in the wind. If your car is properly tunes, tires inflated properly and you don't have a heavy foot you will get the best mpg you can get. Some folks say using synthetic oil will help mpg, but I use it in all my cars and I haven't seen a mpg gain.

[dolemite]

I use the synth because I like giving my car extra love, but a better lubricated engine sure won't get worse mileage. Tires, driving habits, rpm's - those seem to make the most difference. There's some speculation about cold air intake, throttle body spacers, etc.'s effect on mileage.. haven't tried those yet.

[Mean Green]

Originally Posted by dolemite

I use the synth because I like giving my car extra love, but a better lubricated engine sure won't get worse mileage. Tires, driving habits, rpm's - those seem to make the most difference. There's some speculation about cold air intake, throttle body spacers, etc.'s effect on mileage.. haven't tried those yet.

No help for mpg there. Here is a good read for supposedly gas savers.

Looking For A Miracle: We Test Automotive 'Fuel Savers' - Popular Mechanics

[b1ken]

Hi, Again. Thanks for the replies. I teach at a State School and a few years back a student did a report on the effect of synthetic vs. dino oil. We did the test with a 530 HP 440 engine that I used in my drag car. We started out with 10-40 Pennzoil dino (short for dinosaur) oil. The engine made 529 HP. We then swapped that oil for 10-30 Pennzoil synthetic. The power was DOWN to 524 HP. We then went to Mobil I 5-30. HP was 524 again. The last oil was Mobil I 0-5. This time the power was back almost to the original at 528. Now you might say that this doesn't predict what the gas mileage results would be but I feel if the engine lost power it must have increased internal friction. I could be wrong but I still don't think there's any mileage increase from synthetic oil. I had another student who tested the effect of running premium fuel vs. regular. He claims that he did get an improvement but that it took a couple of tankfuls to get it. The feeling is that the computer advanced the timing over a period of time due to the knock sensor communicating with the computer. Sounds reasonable, but I haven't tried it myself. 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!

[Hooligan]

Thanks, that is good info both on the type of oil and gasoline.