pgf@hou5h.UUCP (11/03/83)
It seems to me that some gasolines give my car better mileage than others--
its more of a gut feeling than measured experience, but I was wondering
if others had noticed it, or knew it to be true. Are the "better" brands
of gas (e.g. Amoco) more chock-full-o-energy than the cheap ones (e.g. Buy-
Rite)?
On the subject (sort of), has anyone had any experience with water
injection? I know it can reduce detonation (pinging), and is used in
high compression or boosted engines, but will it help the average car?
How serious is the increased rusting of the exhaust system?
Paul Fox, AT&T Information Systems Laboratories
Holmdel, NJ
ihnp4!hou5f!pgf or vax135!hou5h!pgfjj@rabbit.UUCP (11/03/83)
I know (from experience) that Chrysler Lean Burn ignition systems will behave very oddly with Exxon gas. <I don't know why, but I had trouble, took it to the dealer, and he drove it about a mile and told me not to use Exxon gas, and he was right.> It has something to do with the additives in the gas confusing the Oxygen sensor in the exhaust pipe?? You didn't mention what sort of car you have. (Apparantly the additive makes the oxygen sensor think that the car is running VERY lean, so it opens the variable jets in the carb more. <you've never seen so many servos!> Thus, you get RICH, RICH mixtures, and barely useful operation.) -- o O from the pyrolagnic keyboard of ~ rabbit!jj -v-v- \^_^/
wally@cornell.UUCP (Wally Dietrich) (11/04/83)
While I have a strong "gut feeling" that some brands of gas are better than others, I have it from pretty reliable sources that in many cases, the same gas trucks that deliver gas to name-brand service stations deliver it to self-service places (7-11, etc.). (I mean they deliver the same gas too.) I suspect that the best thing to do is find a place whose gas gives you good mileage at a good price and then go there whenever possible.
amyh@fluke.UUCP (Amy Heidner) (11/09/83)
Aside from some very cheap brands, all brands of the same octane rating
seemed to provide the same mileage in the five vehicles I've driven
since I started paying attention to mileage some 7 years ago. What
does make a difference is octance rating. In both of our small pickups
(the only vehicles I've run the experiment on), the gasoline cost per
mile was the same for premium unleaded and regular unleaded; the
mileage gain from premium offset its increased cost. However, the
trucks ran much better (less rattle & ping) on the premium.
Amy Heidner John Fluke Mfg Everett, WA
{sscvax|teltone|microsoft|lbl-csam|uw-beaver}!fluke!amyhdswankii@uok.UUCP (11/10/83)
#R:hou5h:-30100:uok:500004:000:799 uok!dswankii Nov 7 16:35:00 1983 Some types of gas could have different btu ratings due to water in the gas or use of alcohol as an octane booster. Less btu means less heat and because your engine is a heat machine that means less miles per gallon. As far as water injection goes, water injection by itself will not give you better milage. Water injection controles pinging by cooling the combustion gasses and slowing the rate of burn. By itself this will result in less economy (see above). What gives better milage is that you can set the tune of the engine for better economy (advance the spark,etc) and water injection will control knock. If the system provides the right amount of water, no adverse problems will result. I have not noticed any increase in exhaust rust. David Swank II ctvax!uokvax!uok!dswankii
larry@ihuxf.UUCP (11/11/83)
I have followed the gas mileage on my cars VERY carefully for about 12 years now. When I first started, I carefullly noted the brand of gas --hoping to find "which gave the best mileage". Well, I hate to disappoint everyone, but in the average ``real use'' driving, your mileage fluctuates too much to be able to pin down any "gains" to a brand. After all, even if a particular brand DID give better mileage (which would be pretty tricky for the same OCTANE ratings) - then just the difference of two or three stop lights (idling) would destroy the minute gains. -- Larry Marek ihnp4!ihuxf!larry
mikey@trsvax.UUCP (11/20/83)
#R:hou5h:-30100:trsvax:55200021:000:513 trsvax!mikey Nov 10 17:47:00 1983 I don't know about the mileage that much, but some brands of gas are extreemely different. I tried a tank of Texaco Sky Chief (high octane) in my CBX and it took 4 tanks of Arco Supreme untill it would run right again. I suspect that the majors all have their own additive combinations that they use, although the independents may buy a different gas each week. I gave up using shoping for gas for my bike and I go to only one dealer and mix the unleaded to unleaded to boost the octane for the bike. Mikey