what fuel octane do you run in your 4.0 i6 and why?

Ryan Marshall
205

Asked by Sep 15, 2009 at 04:46 PM about the Jeep Grand Cherokee

Question type: General

5 Answers

Andrew Hartman
235

87. It's the cheapest and the 4.0 is a 35 year old design that does not require anything higher for performance. Anything more than 87 is just wasting money.

Ryan Marshall
205

thx for your response. i was making sure because ive heard mixed responses.

Nathan Casteel
95

Don't use 90 octane. Just use Unleaded 87 octane. Using a higher octane fuel is only more expensive, and instead of conserving fuel, it will only burn/use it faster. The inline 6 was only meant to have 87, and it could possibly overwork your engine if you try and go higher. Besides, 87 is the cheapest... why spend more?

cliff212
110

I was told by a mechanic to use only reg (85 OR 87 OCT) and not to use the 10% ethenol as this causes the senors to assume that the engine is running lean and will increase the fuel consumption until the 02 sensor is satisfied. I have a 99 with 83K and has not had anything but regular in it. Still runs exceptionally well.

2 out of 2 people think this is helpful.
chrisnemo
20

i live in sweden and the low octane here is 95,i run my grand cherokee laredo 4,0 on this,no problems,87 or 89 octane can be had in former east europe or russia,but not in the west,95 gives you a lot of pulling and towingpower

Your Answer

Add photo

Related Questions

  • how long does a grand cherokee last? (mileage wise) 29 answers

    how long does a grand cherokee 1999 last? (mileage wise) i would like to buy one but do you know if this car have some problem ??? thanks

    1999 Jeep Grand Cherokee Laredo 4WD

    -

    General

  • Why 93 Grand Cherokee Laredos? 2 answers

    Hi, I just recovered my 93 Grand Cherokee Laredo after it was stolen two weeks ago. I come to find that the 93 Jeep Grand Cherokee Laredo is the 9th most popular car to be stolen in Washington state. ...

    1993 Jeep Grand Cherokee Laredo 4WD

    -

    General

  • why does my jeep shake mostly while idling? 1 answer

    Ok i just did a block swap and got.the.truck running . new.head gasket set. but now jeeps motor is jumpy so tightened the mounts.i noticed most of the noise was coming from the exhaust. Engine ligh...

    1999 Jeep Grand Cherokee Laredo 4WD

    -

    General

  • Why is my Jeep stalling when I'm coming to a stop or idling? 3 answers

    I've owned my jeep about a year and have never really had problems with it stalling on me until now. I've tired numerous things, but nothing seems to fix it. My engine light recently came on and ...

    2001 Jeep Grand Cherokee Laredo 4WD

    -

    General

  • Swapped Jeep 4.0 with crate motor. Will crank, wont start. 2 answers

    I made sure the cam position sensor was aligned to #1 at top dead center. The fuel pump isn't getting power, I checked with a meter. It turns on with a jumper in the relay socket. It will not sta...

    2004 Jeep Grand Cherokee Laredo

    -

    Maintenance & Repair

Grand Cherokee

Looking for a Used Grand Cherokee in your area?

CarGurus has 73,258 nationwide Grand Cherokee listings starting at $495.

ZIP:

Search Jeep Grand Cherokee Questions

Jeep Grand Cherokee Experts

#1 inuevafreak
inuevafreak
Reputation 1,750
#2 Tom Demyan
Tom Demyan
Reputation 1,560
#3 thejeepdoctor
thejeepdoctor
Reputation 1,460
View All

Related Models For Sale

Used Jeep Cherokee"
314 Great Deals out of 52,059 listings starting at $2,495
Used Jeep Wrangler"
350 Great Deals out of 14,939 listings starting at $2,795
Used Ford Explorer"
1,169 Great Deals out of 68,335 listings starting at $999
Used Toyota 4Runner"
318 Great Deals out of 16,981 listings starting at $1,900
Used Jeep Wrangler Unlimited"
260 Great Deals out of 31,316 listings starting at $8,995
Used Dodge Durango"
330 Great Deals out of 20,859 listings starting at $1,400
Used Chevrolet Tahoe"
997 Great Deals out of 36,593 listings starting at $2,095
Used Dodge Charger"
591 Great Deals out of 30,724 listings starting at $2,343
Used Ford F-150"
2,865 Great Deals out of 204,666 listings starting at $1,500
Used Jeep Liberty"
356 Great Deals out of 9,168 listings starting at $1,350
Used Chevrolet Silverado 1500"
2,194 Great Deals out of 135,147 listings starting at $1,500
Used BMW X5"
491 Great Deals out of 14,202 listings starting at $2,900
Used Honda Accord"
1,201 Great Deals out of 75,065 listings starting at $1,395
Used Ford Mustang"
751 Great Deals out of 39,922 listings starting at $1,600
Used Dodge Challenger"
387 Great Deals out of 24,182 listings starting at $8,995