99 Suburban - uphill weak

[BlueSuburban]

Brand new member. Just acquired a 99 Suburban 1500LS (with 4wd) with 165,000 miles. It seems to run pretty well, a little week on the up hills.

Any suggestions?

Also, what octane fuel should I run?

 

[zora]

octane requirement is 87 or higher below is a link to the owners manual. Since you have no
records I assume of maintenance, you could do a tuneup of fuel filter, air filter, spark plugs, etc.
http://www.vadengmpp.com/owners-manual/chevrolet/1999-Chevrolet-Suburban.pdf

 

[Chuzz]

In addition to what zora suggested, have the exhaust checked for a cat con that may be clogging.