>
>Hi all -
>
>Thought this might be an interesting topic for discussion. I was in a
>conversation (argument?) with a couple of friends this weekend regarding
>regular unleaded vs. premium unleaded and what should be used in which
>engines/applications, etc.
>
>I'm driving a '96 Dakota V8 magnum, and the salesperson told me to just run
>87 octane gas, that if I used the super unleaded my truck would "develop an
>appetite for the super"... He was also saying that *ALL* the new gasolines
>have detergent qualities, and the higher-octane gases won't keep your
>engine any cleaner than the reg. unleaded. My truck has been running fine
>on the 87, and I was talking about this with one of my friends who has an
>'86 Laser Turbo with 162K miles on it, and he said "if I didn't run super
>unleaded in my car, I don't think it would've made it to 162K miles..."
> This makes some sense to me, as his car is a turbo 4-cylinder, and has to
>work harder and rev higher, so it probably benefits from the higher-octane
>gas. The other guy who was with us during this discussion, has a '70 'Cuda
>340 six-pack, and he ALWAYS runs super unleaded in his car, and again I
>don't blame him, it's an older engine which was designed for LEADED fuel, so
>he uses both lead additive, and octane booster for maximum performance from
>his 340. My question is, since I'm only driving this sucker as a DD, and I
>may put some minor mods (in the future) in there to increase performance
>(K&N filter, MP computer, etc.), am I really making a mistake by running 87
>octane in my truck?? Should I spend the extra $$$ for the super?? I'm
>curious as to what other folks are doing?? Thanks.
>
>Ned Vogler
>(nvogler@rghosp.chime.org)
>'96 Dakota SLT V8 5-sp 4x4 Club Cab
>
>
Cars with higher compression ratios may require super unleaded. Thus, turbo
charged cars typically require higher octane than non-turbo charged cars. The
designed timing advance also has an effect on the need for higher octane fuel.
Also, older vehicles with significant carbon buildup in the cylinders may
require super since the carbon may effectively raise the compression ratio.
In a car designed for 87 octane, higher octanes are a waste of money. Period.
The MP computer in the Dakota requires higher (93, I think) octane.
Therefore, if you add that in the future, you will need to switch to super
unleaded.
I can't comment on the detergent qualities of regular vs. super unleaded fuel.
If you are running cheap unleaded without detergent, you may want to use a can
of injector cleaner once in a while.
Here are a few of my personal data points:
Before I purchased my Dakota, I had a 1989 Subaru which I had to run 89 in or
else it would ping tremendously. I also had a 1988 Dodge D150 van (318, V8)
which I either used 86 or 87 octane depending what was available. Never had
any problems with the van, even when towing a 5000 lb trailer and carrying 5
people plus gear. I never worried about fuel detergency, but I do use
injector cleaner once in a while.
My previous car was a 1986 Mazda 626 GT Turbo which my father is currently
driving. After experimenting with fuel octanes, I found this car ran fine on
89. It currently has 170,000 miles on it, runs great, and burns about 0.5
quart of oil every 3,000 miles. My father has driven it the last 20,000 miles
on 87 octane without any noticeable pinging or problems.
Just my two cents...
Moise Solomon
msolomon@mitre.org
1996 Dakota SLT 5.2L 4X4 Club Cab
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