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What kind of gas and oil to put in a classic car
John Paul, AAA Northeast's Car Doctor, answers a question from a reader who inherited a 1970 Pontiac.
Q. My father passed away and left me his 1970 Pontiac LeMans with a 350-cubic-inch. V-8 engine. Would you be able to help me with what type of gas and oil I should use in it? I have no idea what my dad used, and I want to treat the car right.
A. Depending on how you are going to drive it, regular 87 octane should be fine. If you hear an engine knock (detonation) then move up to premium. These engines were designed for leaded fuel and if the engine is all original and you are going to drive the car every day, then add a lead additive to the fuel. If this is only going to be a car that you use to go out for ice cream on the weekends this is not necessary. I would use 10W-30 or 10W-40 oil. Many people with older cars use Shell Rotella T5 oil which is a synthetic blend-first formulated for diesels. But any quality 10W-40 10W-30 designed for older engines is fine. Considering the car is 53 years old I would not use full synthetic oil. Synthetic oil will not cause a leak, but it may find existing leaks.
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Q. Upon starting our 1998 Buick, the light for the airbag stays on. Should it? All the other dash lights go on momentarily then go off. The car was not driven much but it started up and ran a bit over the last three years.
A. The airbag/SRS light should come on for a second or two and go off. The airbag system does its own self check upon starting and when the system is deemed ok, turns the light off. At this point, the airbag system and other computer components should be tested using a quality scan tool. Once you have computer codes you will get a better idea how to proceed.
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Q. The alarm on my older Chevy goes off in the middle of the night. My repair shop has told me they think it is the airbag causing the issue. Could this be, and can I just disconnect the horn?
A. The alarm going off may be related to the airbag, and on some GM vehicles the issue was that the airbag cover would shrink during cold weather and activate the horn. The proper repair is to replace the airbag. Regarding disconnecting the horn, the horn is a part of the safety system and something I wouldn’t recommend.
Q. I have a 2019 Subaru Outback base model. Lately the radio and/or touchscreen have been acting weirdly. Sometimes when the radio is on FM it will start to change stations as if I pressed “scan.” When in SXM it will leave the station and go to an SXM screen. When these things happen, the screen and buttons become unusable. I read about a reset procedure which seems to work sometimes for a day or two. Also, I am sure that I used to have blind-spot monitoring but now I don’t.
A. Blind-spot monitoring and backup sensors were an option and recently I answered a email from a reader who thought he lost his back up sensors. Come to find out, the car never had this function. Regarding the touch screen, there are dozens of technical bulletins suggesting everything from disconnecting the battery to multiple software updates. There was even one that suggested just a thorough cleaning of the touch screen with a microfiber cloth and Sprayway window cleaner. At this point you would probably be best served to bring the car to the dealer and let them check to see that the software is up to date.
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John Paul is AAA Northeast’s Car Doctor. He has over 40 years of experience in the automotive business and is an ASE-certified master technician. E-mail your Car Doctor question to [email protected]. Listen to the Car Doctor podcast at johnfpaul.podbean.com.
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