98 GMC 7.4 rebuilt recommended oil grade

Asked by GuruCQBG7 Feb 26, 2019 at 03:41 AM about the 1998 GMC Sierra 2500 2 Dr C2500 SL Extended Cab LB HD

Question type: Maintenance & Repair

I just had my 98 GMC 7.4 motor rebuilt. The grade on the oil cap is 5-30. The
guy at the rebuild shop recommended 20-50. I live in the San Joaquin valley
in California where it's a 100 plus all summer. This truck will be pulling a 28 ft
5th wheel most of the time. Want to get your guys opinion. Thanks

1 Answer

I would only use 20W50 in an oil burner. You will lose some power and fuel economy using thick oil. Try 10W40 before using 20W50.

Your Answer:

CarGurus Experts

  • #1
    Rowefast
    Reputation
    180
  • #2
    Gene Arnett
    Reputation
    170
  • #3
    mikeatpriestlake
    Reputation
    70
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Chevrolet Silverado 2500HD
16 Great Deals out of 1,285 listings starting at $8,995
Used GMC Sierra 1500
148 Great Deals out of 7,258 listings starting at $3,950
Used Ford F-250 Super Duty
24 Great Deals out of 1,204 listings starting at $7,995
Used Chevrolet Silverado 1500
202 Great Deals out of 5,975 listings starting at $2,975
Used Ford F-150
321 Great Deals out of 14,968 listings starting at $1,712
Used Dodge RAM 2500
23 listings starting at $9,975
Used GMC Yukon
16 Great Deals out of 929 listings starting at $1,225
Used Chevrolet Silverado 2500
2 listings starting at $12,500
Used Ford F-250
6 listings
Used Ford F-350 Super Duty
39 Great Deals out of 2,598 listings starting at $8,888

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.