Are prolonged interstate speeds (78-79mph) hard on small 1.5L engine?


I just started a daily commute of 85 miles each way and I am wondering if it is as bad for my car as it is on my mind.

My question…

My car is a Honda Fit with a small 1.5L engine. I usually cruise at a constant speed of 78-79mph for about 80 miles of the commute each way. The Fit has a 5-speed and in 5th gear the engine is humming at around 3,800-3,900 RPM. The question is, as I put around 1k on my car a week, is it bad for my engine to run it this way? I’ve heard highways miles are better as far as brakes, starters, so on but I am wondering if I am just not driving a car suitable for my commute.

Would it be beneficial to ditch the small 1.5L engine for a bigger V6? Or, is it perfectly fine to drive at a constant interstate speed with RPMs near 4,000 RPM. What problems could this potentially cause? Any recommended maintenance tips for this type of wear and tear?

Thanks guys!

I wouldn’t worry about it, Honda has a long history of designing outstanding engine that can handle high rpms. Just make sure you keep up with the oil changes, using the type specified.

Honda builds good engines. Even though your engine will wear a bit faster, it should still outlast most other things on the car. I wouldn’t worry. As always, make sure you check your oil regularly.

I’d imagine this isn’t the most comfortable car for a long commute, so perhaps that’s the bigger concern here.

I’ve done a number of things to make the commute more bearable. First, I got a lumbar support pillow from Amazon as the seats in the Fit are not the most comfortable. This did the trick. Second, I make it a habit to listen to podcasts (such as car talk) or music as I believe the sound masks the prominent engine/road noise. Third, I am cheap so I constantly rationalize hanging on to the Fit (as it is almost paid off) since it only has 52k on the odo.

Eventually I would like to upgrade to a more comfortable ride but I am determined to make the Fit work. Maybe I’ll get a prius if gas prices shoot up. I use to average around 36-37mpg on my old commute (HWY speeds between 50-60mph) but now I am getting around 29-30mpg.

Thanks for the response. I change the oil per the “maintenance minder” which is about every 9-11k depending on my driving habits. I use Honda Oil and nothing synthetic. Are there special oils for this type of use?

Thanks again!!!

I’d be a little leery of a 9-11k oil change interval on conventional oil…but I’m no Honda expert nor do I know how good their oil is. I’d push 10k in any of my vehicles running a good synthetic and a good filter, but that’s just me.

Your Fit will be fine.
But you will pile on the miles. No way of avoiding that.

For the record, I once commuted 103 miles each way for a year in a brand new Toyota pickup. With a bench seat. I ultimately got 338,000 miles out of it before it got hit and totaled.

The engine will last a good long time with this kind of use, don’t worry about it.

The easiest way to improve the ride is to install softer riding tires. Finding ones that will also not hurt, but improve your mileage is the hard part. Soft vs mileage is usually a trade-off tires make. allows you to compare these features and more of many tires that fit your Fit.

As for maximizing your daily commute mileage, synthetic oil will make a small difference and you can safely extend the oil change interval to the longest the Fit recommends. Inflate your tires to the manufacturer’s recommended, and try 2 psi more. It will help the MPG’s a bit more. You can buy mileage meters that plug into your diagnostic (OBD 2) port that show instantaneous mileage. Use that to improve your driving style and I’d bet you can easily improve that 29-30 mpg by 3 mpg.

Thanks everyone! Lot’s of great input here.

I am at like 4/32" on my tires and will be getting new tires this summer so I will check out TireRack to see what the best blend of soft/mileage tires I can get. I was considering a set of Michelins but maybe I will need to explore a softer tire. Also, I will play with the inflation a bit.

Miles will mount up for sure. I will inquire about any synthetic oil options at my next oil change, which is probably 2 weeks away at this high rate of use.

I certainly feel better that my Engine isn’t going to blow up at 95k or anything like that. Thanks all!

My wife had a 2002 Hyundai Accent when we got married. It had a tiny 4 cyl and a 5 spd standard. I always said that there was no way in the world that it had an actual overdrive. 5th gear didn’t sound like it was “settling down” for highway speeds at all. It didn’t had a tach, but I swear it didn’t drop any more than 200 or 300 rpms from 4th to 5th gear. That car sounded like a screaming meemee over 65mph. I predicted for years that the engine was going to fly to pieces, but it never did. In the end, the cheap Hyundai clutch, motor & tranny mounts and even bolt heads fell about before the little engine did. Northern road salt rusted too many bolt head round for me to even change a belt without hours of work. When the clutch started slipping at 100k, I sent it to craigslist and said bye bye.
For $9,000 brand new, she got 100k miles worth of 41 mpg for 5 years. can’t beat that with a stick. Got $2,200 back in the end too.

To answer your question, I have to assume that Honda, in their infinite wisdom, knew that you’d be driving exactly how you are in that car. If you follow their specified maintenance plan to a “T”, I do not see how you can go wrong. If it makes you feel any better, dial back the throttle to 74 mph and give it a little break. You’d be surprised at how much better mpg you’ll get for an extra 5 to 8 minutes worth of driving.

I too live in northern salt-the-roads country. Did you ever clean the engine bay to remove salt after winters?

With the 74mph its a trade off of time vs efficiency. I am already driving 1 hr and 15 mins at 78-79mph. I figure I am saving about a half hour of my day (15 mins each way) giving it a few more mph on the interstate which at five days a week would give me an extra 2.5 hours of my life!

But, you are probably right. I could dial back a bit for safety, efficiency, and maybe to avoid a ticket or two.

Glad to hear you had such good luck with your Accent. I’d driven a friends Hyundai Accent and it was surprisingly fun (he had a 5spd as well).

The Keys To Long Commutes Are A Good Sound System And The Programming (Whatever You Enjoy) To Go With It, And Some Lumbar Support. Looks Like You’ve Got It!

Oh, and I forgot. The other one that helped me that I no longer have access to is youth. Have you got any? Aging skeletons and commuting don’t mix as well. Make sure you find make some time not consumed by driving to get some cardio and stretching exercises.

Good for you to make this sacrifice and give it whatever it takes to get the job done! Some lazier sorts would never do it.


Don’t expect a lot better mpgs with a Prius at 80 mph, their benefit is more in the city.


I most certainly could not do this commute in a Honda Fit with any sort of back issues. I swear the seat is a piece of cardboard with cloth.

Excellent ProTIP about hitting the gym. I actually pass one EVERY day right when I get home. For my mind/body I should probably sign up!

I took on the commute because my Fiancé landed a good job and there wasn’t any civilization between her work and my work so I sucked it up and took on the challenge. I’ve got Spotify, Podcasts, call friends, and the Radio to keep me sane. I am also gonna start some Audiobooks.

I don’t see myself doing this much longer than 2-3 years. Past that, I think I will need to make a change because I don’t wanna waste years of my life in a car.

I am sure you know this but as a reminder speeding tickets are expensive and can really cause your insurance rates to increase.

Gym Idea Sounds Good. Although Your Spare time Is Precious, It Won’t Be A Waste Of Any. I Don’t Know If You Work Out, Now, But It Does Help In Keeping One Sane.

I Get Such A Boost From My Air-Dyne And Treadmill That I Can Actually Make It Through This Insane, Long Depressing Winter Weather (Hopefully… That Lousy Weather Has Returned). It Does Become Addictive Because It’s So Invigorating! (The Exercise, Not The Weather).


Lots of places are 75 mph now, so 78-79 usually won’t get a ticket.

VOLVO - I’m going about 8-9 mph over the limit. You think that is high risk? I figure a 78-79mph ticket costs the same as a 75mph ticket.

CSA - Don’t work out like I should. Again, this is great advice for long commuters.

Texas - I agree maybe the Prius will not be worth the extra money and steep depreciation for a few mpgs. Good point.

I can’t speak for your area but on I-40 in eastern Oklahoma 3 or 4 miles over will get you a ticket for over $100 to often for me to run the risk. 5 MPH over should be fine, 8 MPH not so much.

I use Honda Oil and nothing synthetic.

Honda doesn’t make oil…never have…it’s made for them by one of the oil companies…and probably changes manufacturer every 5 yeasr.

9k miles is way too long.

Sorry, Honda “brand” Oil is what I use. OEM.

I go by the Honda Maintenance Minder which is a small percentage gauge on the dash that when it gets down to 15% gives maintenance codes for shops to follow. Basically the recommended maintenance is programmed into the car.

It usually takes 9-11k before the car indicates maintenance is required. It only takes me 4-5 months to get 9-11k so I would say my intervals are well within the “or six months” criteria. Anyone every following the Honda MM and had the engine blow up?

Should I over ride and get an oil change every 3-5k or every other month?