Subject: Actually, windhund, using higher grade gas than your engine requires is wasteful Author: leersmd : member since April, 2005 : 1626 posts Posted on: 2006-06-01 23:54:59

I did the usual, you know, you got a V12, so feed it the best! Wait a minute though, that V12 pushes 8.8 compression, it really doesn't need the high octane, in fact, it is detrimental to its performance. Think about it, octane retards spark for engines with high compression so they don't predetonate, what good does that do for an engine that is only at 8.8? I did a lot of research on the topic and reluctantly went to the lower grade - and my reluctance was not because it was BETTER for the engine (which it is AND it'll better your mileage per gallon) but I could no longer have that thought that I drove a car that needed "Premium" gas!

1990 750iL
1990 525i
3, no wait, 4 cats that love to look at me quizzically while I'm working on the '7


DC77705

• How many Miles per gallon do you get on your E32? - AL 2006-06-01 10:13:14 (165 views)
  • AVG MPH=26 AVG MPG=17.4 93 74OIL (nt) - shadetree/pete 2006-06-06 14:53:10 (88 views)
  • Could be the gearing! - mikeym 2006-06-04 13:01:45 (71 views)
  • 20 +/- Mpg all highway - eldragon 2006-06-04 12:39:45 (87 views)
  • look at the pic (pic) - shogun 2006-06-04 05:25:16 (205 views)
    • was he going off the cliff or towed when pic was taken? - sinij 2006-06-04 13:01:15 (84 views)
    • Re: look at the pic - mikeym 2006-06-04 12:56:56 (72 views)
    • Re: look at the pic - mikeym 2006-06-04 12:35:08 (67 views)
  • 14.3-14.7 litres/100km = 16.5mpg - Nick (Australia) 2006-06-03 09:33:58 (77 views)
  • I drive my '88 750iL on the autobahn about 90% of the time... - chrisf 2006-06-02 08:01:56 (144 views)
  • 16.8 MPG average - 740ipilot 2006-06-01 23:33:25 (97 views)
    • Glad to see you tried (url) - Shayne 2006-06-02 09:55:02 (86 views)
      • I had to! - 740ipilot 2006-06-02 15:20:24 (89 views)
        • Re: I had to! - Shayne 2006-06-02 15:59:37 (77 views)
          • I know little of chemistry, it's one of the few things on this planet - 740ipilot 2006-06-02 21:17:34 (164 views)
            • Re: I know little of chemistry, (url) - Shayne 2006-06-03 13:52:15 (77 views)
  • 735i 5-spd: 14-15 city, 25-26 hwy , 18 mixed . . . - gale 2006-06-01 21:00:40 (75 views)
  • Re: How many Miles per gallon do you get on your E32? - gus 2006-06-01 20:41:57 (127 views)
  • Manually computed average works out to 15.3 mpg over 2 months - bcweir 2006-06-01 20:06:15 (89 views)
    • BC, I really hate doing this, but if you use your gas tank capacity - leersmd 2006-06-02 00:36:46 (102 views)
    • Get some REAL miles under your belt and I'll bet you - leersmd 2006-06-01 23:36:43 (85 views)
  • 18 mpg average (nt) - RM 93 740iL 2006-06-01 19:28:41 (73 views)
  • 14.9 average. 89 750IL (nt) - Paparon 2006-06-01 19:10:37 (80 views)
    • wow!! is that ALL highway? (nt) - plbowler 2006-06-01 21:00:40 (80 views)
      • combo miles........Remeber it is HER car (nt) - Paparon 2006-06-02 11:53:27 (61 views)
        • 15.9 combined? thats insane!! I wish I drove like that (nt) - plbowler 2006-06-02 20:41:08 (55 views)
          • oops, 14.9 (nt) - plbowler 2006-06-02 20:42:48 (57 views)
  • 10.4 l/100 km hwy and 13.1l/100km combined - Shayne 2006-06-01 18:22:36 (80 views)
  • Pretty close to mine - nostness 2006-06-01 15:44:16 (90 views)
    • I switched from 89 to 87 octane recently and now my car runs better....I - windhund 2006-06-01 18:45:18 (96 views)
      • Maybe because of higher compression? (nt) - nostness 2006-06-01 19:16:00 (58 views)
        • Actually, windhund, using higher grade gas than your engine requires is wasteful - leersmd 2006-06-01 23:54:59 (144 views)
          • High octane retards spark!? - Shayne 2006-06-02 10:43:55 (109 views)
            • Shayne, thanks for clarifying, pl had it right about - leersmd 2006-06-02 13:35:46 (80 views)
            • I think he meant it explodes later with repect to compression - plbowler 2006-06-02 11:28:36 (76 views)
          • leersmd is right on the money; I'm sticking with the 87 octane (nt) - windhund 2006-06-02 05:58:13 (64 views)
    • I agree with you! I experienced that too by switching to a 91 octane (url) - AL 2006-06-01 16:52:33 (103 views)
  • Re: How many Miles per gallon do you get on your E32? - johan750 2006-06-01 11:58:55 (89 views)
    • Re: How many Miles per gallon do you get on your E32? - jrs740 2006-06-01 20:38:53 (108 views)
  • 19 city / 25 hwy ('89 735i manual tranny) (nt) - DavidC 2006-06-01 10:51:33 (66 views)
    • 12 city: 21-23 highway (nt) - leersmd 2006-06-01 12:15:32 (72 views)
  • Sounds about right. - plbowler 2006-06-01 10:23:54 (84 views)
    • wait a minute, you have a 735, your mileage is too low (nt) - plbowler 2006-06-01 10:58:13 (90 views)
      • I'll try and calculate my MPG manually. Could it be possible its - AL 2006-06-01 11:15:42 (75 views)
        • I get 20-22 mpg highway on my rebuilt M30! (nt) - mikey735i 2006-06-03 20:56:55 (63 views)