Chasgood, tell us about your car.
 

You mentioned that you have to use 91 octane in your car.  Is this the factory recommended fuel?  If so, do you know the compression ratio for your motor?  That thing must be hella powerful.

front end conversion
 

<p>The owners manual says 91 octane gasolines are recommended but not required. The use of lower octane gasolines will result in reduced acceleration performance.</p><p>the PT Cruiser GT has a high output 2.4L turbo engine. 215hp at 5000rpm and 245ft-lbs torque at 3600rpm&nbsp;</p><p>Not sure what the compresion ratio is but the turbo boost tops at 12.8 psi.&nbsp;</p><p>Consumer reports lists the performance as follows.</p><table cellspacing="0" cellpadding="2" border="0" bgcolor="white"><tbody><tr bgcolor="#deeef8"><td valign="top" class="n11">0-30 mph, sec.</td><td align="right" class="n11"> 2.8</td></tr>
<tr bgcolor="#eef6fb"><td valign="top" class="n11">0-60 mph, sec.</td><td align="right" class="n11"> 7.0</td></tr>
<tr bgcolor="#deeef8"><td valign="top" class="n11">Quarter mile, sec.</td><td align="right" class="n11"> 15.6</td></tr>
<tr bgcolor="#eef6fb"><td valign="top" class="n11">Quarter mile, mph</td><td align="right" class="n11">91</td></tr>
<tr bgcolor="#deeef8"><td valign="top" class="n11">45-65 mph, sec.</td><td align="right" class="n11"> 4.3</td></tr></tbody></table><table cellspacing="0" cellpadding="2" border="0" bgcolor="white"><tbody><tr bgcolor="#eef6fb"><td valign="top" class="n11">CU's overall mileage, mpg</td><td align="right" class="n11">22</td></tr>
<tr bgcolor="#deeef8"><td valign="top" class="n11">CU's city/highway, mpg</td><td align="right" class="n11">17/27</td></tr>
<tr bgcolor="#eef6fb"><td valign="top" class="n11">CU's 150-mile trip, mpg</td><td align="right" class="n11">25</td></tr></tbody></table><p>&nbsp;Its not a hotrod but has plenty of power to get on the highway on ramp or pass with no effert at all.&nbsp; ;-)<br /></p>

Wow
 

<p>holy crap.&nbsp; That's one mean machine.&nbsp; If I walked up to other honda drivers and told them I had a 215hp engine at 5000rpm they would think I was some sort of God.</p><p>&nbsp;Actually, I doubt that a little honda like mine could do much with 215 horses.&nbsp; It might just sit there and spin the tires.&nbsp; Any idea how much it weighs?</p><p>I think that the first thing that you can do to raise yourmileage is to use lower octane gas.&nbsp; With your obd2 knock sensor (as you already know) it will lower performance and as a result raise your fuel economy.&nbsp; </p><p>Did you buy it new or used?<br />&nbsp;</p>

Questions about PCV
 

The PT weighs 3100 lbs. So it is about 500 to 700 pounds heavier than a Civic.

Actually I have tried a few tanks of regular gas and for some reason it didnt change the mpg one bit. The car took a big performance hit. Right now I am trying the mid grade gas (89 octane). 89 seems to give the car almost all the performance 91 gives while saving 9 cents a gallon. Not saving gas but I am saving money.