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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;mso-fareast-language:EN-US'>Interesting. I remember the 5 star label on 3500S. I doubt, tho\u2019 that a/c costs much fuel mileage. I\u2019d guess 1%!<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt'>Geoffrey W. McCarthy MD MBA DipAvMed Col USAFMC (ret)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt'>677 NW Melinda Ave<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt'>Portland OR 97210<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt'>503-799-3809 (m)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;mso-fareast-language:EN-US'><o:p> </o:p></span></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'> Rovernet <rovernet-bounces@rovernet.org> <b>On Behalf Of </b>Gordon Reddy via Rovernet<br><b>Sent:</b> Thursday, September 11, 2025 9:13 PM<br><b>To:</b> Rovernet <rovernet@rovernet.org><br><b>Cc:</b> Gordon Reddy <gorgowof@gmail.com><br><b>Subject:</b> Re: [Rovernet] P5B V8 ignition timing<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><span style='font-size:18.0pt'>Interesting, check this out.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'><a href="https://aircooledbug.co.uk/usa-versus-uk-fuel-octane/" target="_blank">https://aircooledbug.co.uk/usa-versus-uk-fuel-octane/</a><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'>Gord<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'>also <o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'>1972 TVR Vixen 2500<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'>...and if I am crazy enough 19?? Citroen 2CV panel van<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Thu, 11 Sept 2025 at 18:05, Gordon Reddy <<a href="mailto:gorgowof@gmail.com" target="_blank">gorgowof@gmail.com</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><div><div><p class=MsoNormal><span style='font-size:18.0pt'>Interesting, I just returned from the UK yesterday and while there noticed octane ratings there are higher. I believe its a different rating system for octane which I was going to check on this evening. I remember my P6 TC2000 had a tag stating use 100 octane but it ran fine on 92. My P5 3 litre runs fine on 91 but its certainly not 10.5:1 more like 8.5:1 It would probably run fine on 87. More knowledgable minds will hopefully contribute. <o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'>Gord<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'>67 P6 TC2000<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'>66 P5 3 litre<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:18.0pt'> <o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Thu, 11 Sept 2025 at 17:54, Jon Stanley via Rovernet <<a href="mailto:rovernet@rovernet.org" target="_blank">rovernet@rovernet.org</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><div><p class=MsoNormal>Hello all, <o:p></o:p></p><div><p class=MsoNormal>I'm trying to tune a stock early 67 P5B V8 with high compression 10.5:1 and is currently set to factory setting of 6 degrees BTDC. The non ethanol fuel I have access to around here in Texas is 90 octane, and adding in a boost probably pushes up to around 92, but the engine was designed and tuned for 100 octane. <o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I'm curious if anyone here has a high compression V8 and what timing they set the engine to and what fuel? Some sources say retard the idle timing possibly all the way to TDC?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Right now the engine runs poorly when cold and on choke, but eventually once warmed up seems to run well. Both carbs have been rebuilt. <o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Regards, <o:p></o:p></p></div><div><p class=MsoNormal>Jon<o:p></o:p></p></div></div><p class=MsoNormal>_______________________________________________<br>Rovernet mailing list<br><a href="mailto:Rovernet@rovernet.org" target="_blank">Rovernet@rovernet.org</a><br><a href="http://rovernet.org/mailman/listinfo/rovernet_rovernet.org" target="_blank">http://rovernet.org/mailman/listinfo/rovernet_rovernet.org</a><o:p></o:p></p></blockquote></div></blockquote></div></div></body></html>