GMC 1995 Jimmy Owner's Manual page 242

Doing Your Own Service Work
If you want to do some of your own service work, you'll want to get the
proper GM Service Manual. It tells you much more about how to service
your vehicle than this manual can. To order the proper service manual, see
"Service Publications" in the Index.
You should keep a record with all parts receipts and list the mileage and the
date of any service work you perform. See "Maintenance Record" in the
Index.
NOTICE:
If you try to do your own service work without knowing enough
about it, your vehicle could be damaged.
Fuel
Use regular unleaded gasoline rated at 87 octane or higher. Use premium
unleaded gasoline rated at 91 octane or higher for high power performance,
when towing a trailer or with a high payload requirement. But when
operating with a light load as a normal condition, you may use middle grade
or regular unleaded gasolines.
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